sir, your quick video was somewhat educational. I live in cold Chicago and recently started having problems with my furnace. After watching your video I was able to get my furnace up in running in about 30 minutes. You just saved me a lot of money and help keep my family warm tonight. For this I thank you very much.
THANK YOU! I was troubleshooting an American Standard Freedom 80 Furnace and your explanation on the flame sensor cleaning fixed our problem and we have heat again. We had two blinking lights which did not really indicate which component was failing and google did not provide much help either. I also appreciated your explanation on the sequence of operations. Good work on this video.
Alvin, thanks for posting! My Goodman GMP075-3 would ignite but the blower motor would not come on. Put the thermostat on "fan only" and fan came right on. Checked the LED code, no problems. Came here to RUclips and saw your videos. Finally, took the vaccuum hose off from the pressure switch and inducer motor, blew a good stream of lung power through the hose, put it back on and abra cadabra furnace now works. Thanks for helping out us home owners!
Thanks so much for the video. I was troubleshooting my furnace and your description of the burners coming on and then immediately turning off described my problem perfectly. I pulled the flame sensor. Cleaned it up as you recommended and the unit began operating normally again. No doubt saved me a service call and potential costly repair.
well done.I now have a good understanding of how a furnace operates .I laughed like hell when you said that someone had forgotten to remove the plastic from the filter.
This was an excellent video for a novice (me) lol, I am very mechanically inclined! After watching this video I can confidently troubleshoot a furnace! Thank You great job explaining everything!!!!!!!
+1 for cleaning out the hose connection between the motor and the pressure switch. That's exactly what my problem was and I just fixed it thanks to your video. Saved me money, I'm sure. Last time I had to call someone out, they wanted to sell me a whole new furnace for $5000. Turned out to be a loose wire. Thanks!
Thank you, thank you, thank you...You just saved me a coupla hundred bucks! The tube, which you described may have rust in it was blocking the ignitor from initiating, which in turn prevented the gas from turning on "sequence of operation".
Thank you for making both of your videos this morning and on the heating side of the system I am currently on the Internet trying to figure out what might possibly be wrong with my Friends heating system he had a problem with the electrical companies connection being loose at the pole we are guessing burn out the circuitboard in the furnace but watching RUclips videos has definitely give me a understanding of how heating and cooling furnaces work I feel if I ever have a problem in the future I could definitely diagnose it I appreciate your time taking to make this video and your other ones
Elven thank you for being so diligent with helping everyone with their problems. Let me tell you what I have diagnosed thus far to see if you can give me some feedback. All of the steps on my Armstrong air Tech 80 that you have discussed in the video are going correct however it apears that the blower is not spinning up to the "RPMs" "that it should. When I compare this unit in my upstairs to the properly operating one in the basement, it seems to be running much slower. Much more lethargic. I hope that's enough info to give you some direction. Thanx again for all your help.
The Main Blower Motors are called Permanent Split Capacitor motors. Because they have a Run Capacitor which is in line with the motor windings. These capacitors make the motor run more efficiently by making the voltage more constant in Alternating Current however when they get weak or go bad they can cause the motor to run slow or not at all. This is where I would start. There are ways to test the capacitor but it requires a special tool so I would just order a new one because they are only a few bucks. Take a look at your motor and follow the wires coming off the motor two brown wires will go to the run capacitor. Remove it and get the capacitor size such as 5 MFD/370 vlt. , 7.5 MFD/440 vlt. etc. It could be that the motor bearings are causing the motor to bind as well and to not get up to full speed also but this condition will also cause the motor to overheat and shut off after a while. This condition can be checked by simply giving the blower wheel a spin and checking to see if the motor bearings seem to be allowing the wheel to spin freely. What you should not have is a blower wheel which comes to an abrupt stop. Manufacturers have been getting away from motors which have bearings that require maintenance oiling if so the motor will not have oil ports. So generally speaking you will need to replace the motor in a case of bad bearings. Good Luck...
Hi Alvin, Is it possible for the blower motor to cause the following problem? I have replaced everything but the two limit switches (rollout and high temp) and I also have not replaced the blower motor (yet). But, my furnace starts (lights) and then goes off after 10 to 30 seconds. I have cleaned the new Flame Sensor with an easer and made sure it was inside the lit flame. The furnace tries to light twice. The first time the flame starts and then goes out after 10 to 30 seconds. The second time the blower motor starts and then ignitor glows, the flame lights and then gas cuts off as before. The blower motor continues to run for 3 to 7 minutes. at which point it comes to a halt (slows and then stops). I do think the motor needs replace but I don't understand how the flame turning off after 10 to 30 second relates to blower or if it should. Any suggestions with me helpful. Roy
RHH1095, If the furnace is firing up then you can rule out having a problem in the roll out switches. The problem sounds like it is in your flame sensor circuit. The circuit board requires a good ground in order for that circuit to work properly make sure your electrical supply ground is connected and that the circuit board is grounded as well as the polarity has not been reversed. The only way your Main blower motor can effect the flame going out is if it is causing the high limit to trip as in not enough air flow or the blower motor shutting down. You should also make sure your high limit is not opening but I doubt that would happen in 10 to 30 seconds after the gas lights. Hope this helps....
RHH1095, I have noticed allot of people get confused with what the Induced draft motor and the Main Blower motor is. I just re-read your message and now I believe you are referring to the Inducer motor. This motor is the one that starts up immediately on a call for heat. The inducer motor can control the gas valve with the vacuum pressure switch but the only way you are going to be able to determine if that is a problem is by the LED diagnostic code. As that could be a momentary problem.
Thank you! Your response has made me trace the terminating point of the flame sensor back to the IFC. (I also replace the IFC board because of burn marks.) The new board does not use the AC-Common wire as the termination point did originally (older furnace). I see now from the IFC manual that the output of the Flame Sensor goes to directly Pin#7 of the nine pin connector. (yes I'm embarrassed but its like asking for driving directions). I believe the behavior of my blower motor just means it needs to be replace (what started this process!). Thanks again.
Doru, On your furnace sometimes the flame can have trouble spreading across the burners if this seems to be happening on your unit it is probably the reason your having the problem with your furnace. If so remove the burners and on the output side there is a flat area which touches one burner to the next this area is called the spreader bar. These flat bars can get filled with water during the summer if you had a leak on your A/C the water will get in there and turn to rust so you need to take something and clean that area out then reinstall the burners. Let me know is it works thanks.
Alvin, thank you so much for answering.The issue is not the water as the gas valve does not release the gas. Unless I knock on the valve with my fingers it will release the gas just as the ignitor gets the signal to turn off.
Hi ALvin. I have measured the voltage on the gas valve and it gives 10.2V until it gets the signal to release the gas. Then the voltage goes to 0 V. Any idea why ? I was expecting to be 24V when the valve was signaled to release the gas.
Bad connection somewhere you're losing your voltage so when the gas valve actually has a draw for current it drops to nothing. Try jumping out the thermostat at R & W if that doesn't work jump out the circuit board on the furnace at R and W. Also try tightening up all your low voltage wiring connections.
Alvin, I have an AMANA 90 Air Command. A couple of years ago I had a lot of problems with condensation in the induction blower. I would take it off, dump the water and then reinstall. It would work for a while but continued to be a problem. The furnace had worked for years so I knew it was not an installation issue. Seemed that there were many post concerning it but none helped. It turned out that the elbow connecting the blower to the vent was the problem. I could not see it from the blower side but when I disconnected the elbow from the vent, there were remnants of a "dirt dauber" nest that had blocked the drain coming from the vent side. Just thought that I would share in case someone else is struggling with that particular issue.
+Michael Braden Thanks and its a good idea to cover you vent pipe outside with a piece of hardware cloth that has 1/4 inch mess screen to prevent that as well other rodents and such. Cheers...
pulled both doors off furnace to vaccum clean burner area when I replaced the filter! ..replaced doors wrong way top and bottom...noticed when my house went cold...put doors back on right way and still no heat...so with your suggestion i reset the roll out switch and BINGO..thanks man!
I have installed a couple of the ventless fireplace logs, and noticed the house had a fume gassy smell. I was thinking of putting one in my home and did a search on consumer reports to see which ones they recommended. I was suprised to find that consumer reports did not recommend any of the ventless heaters because after 5 hours of operation there were none that were still within acceptable standards of carbon monoxide. So no I'm afraid, it is too good to be true. Unless you like fumes.
Thanks for the list of comments. I've reviewed the issues for similar problems and just need a little assurance that I'm headed in the right direction. I have a 12 year old two stage Airquest furnace. I'm installing a new wifi thermostat and and have run into an issue where the blower runs constantly, even when in the fan AUTO mode on the thermostat . After troubleshooting with the thermostat company HELP support, (thermostat tests OK) we discovered that at the furnace blower control panel, with all thermostat wires removed, I have 24 volts from the R to W2, R to W1, R to Y, but only 17 volts from R to G terminal. I went out on a limb and ran a jumper from Y to G to provide 24V at G and retested. The system and blower seemed to be normal in both heat and AC modes. Upon visual examination of the circuit board there are two brown spots around components in the lower part of the board that look like they lead to the G terminal. I assume that the board needs to be replaced. Before I do that, is there any diagnostic to perform on the system? Really appreciate your help with this.
Stranger, Hmm did you mean C to R etc. you got 24 volts? Not saying that you can not get voltage from R to W but those voltages are coming from a coil which is not energized. What I am trying to say is C = common R = Power will give you 24 volts however R and W have the same potential the only way you are going to see power there is when the common is coming through the winding from the other side of a coil or motor. I am going to put up a video to try to explain what I am saying. Stay tuned and I will try to have it up within a few hours. For now simply disconnect all the low voltage wires at the furnace if the blower continues to run then the problem is internal. Be sure and check the High Limit switch to see if it is open that would cause the main blower motor to run. It could be the circuit board but if everything was fine until you installed the thermostat I would start there.
If I suspect flame sensing, I use 105 c rated wire and attach it to the burner, this acts like a flame sensor too, and I terminate the wire where the flame sensor goes or ground or burner ground all on the module of course. this assures you have 2 nice paths home to prove the flame DC signals able to get home.
wow I had no idea there was a circuit board in heaters. They are very complex. I was easily able to diagnose and fix my air conditioning problem last summer by noticeing the shreaded and pathetic blower fan belt laying on the bottom of the box. Was very hard to get the supply place to sell on to a home owner though. What do you think of the wall units you can buy to use in a power outage or small home? 99% efficient they say
Alvin thanks for the informative video. I Have a Ducane M/N 80G1UH070AP12-02. Sometimes works just fine but sometimes the ignitor will light but gas will not come. After three times the furnance will stop and it will take 3 hours to start again. I cleaned up the flame sensor. It seem like a made a difference in that day but it came back to its issues again. The code 7 flashes says Lockout due to no ignition. Any idea what might be?
Thanks for sharing this video. Just awesome that people are still willing to help. My issue is.... Therm calls - check Inducer comes on - check Igniter comes on and bright red - check But then....... Whole unit goes off. Board went black. The light on the board went off so I can't even check the code. I turn the emergency switch off for a sec.pond then back on. Light on board comes back on but no code. So it seems everything works up to gas igniting. I'm stumped. Wondering if you could help with any ideas.
First try disconnecting the power wire going to the gas valve. Then retry the start sequence. It maybe that the coil in the gas valve has shorted out causing an overload in the circuit board. Also you can take an ohm meter and ohm out the coil in the gas valve. I believe the resistance should be around 75 ohms. But if what I'm saying is true then your resistance would be near 0 to 10. My guess is that you have a bad gas valve.
Have a Armstrong furnace shooting a 4 flash code, meaning a roll out or high temp limit open. I metered the limit switches, all good. Aux limit good. Pressure switch good. I jumpered the limit switch out wire, and the return line back, on the 6 pin molex connector on board. I turned on power, and furnace went through the correct start up sequence. Checked with meter between the 2 molex connections and had continuity with and without the jumper. Removed the jumper, applied power... board showing 4 flash again with inducer and fan motor running as before. I think the board is bad, as all limits are passing fine. What do you think Alvin? Furnace is around 9 years old.
Just make sure you are not missing any of the roll out switches. Some models will even have a high limit located on the blower assembly in the event the blower motor is malfunctioning. The high limit and roll out switches are sometimes within a seperate circuit as well so ensure that you have power coming back to the board on both your roll outs and limit if so then it is a bad board. Pull the board and carefully check the back for any signs of where it let the smoke out also play close attention to a weak solder joint which will show as a ring around a soldered pin as it protrudes through the back of the board. These can easily be repaired if you have a soldering iron, but anything more than this you're probably looking at a new board. Take the part number off the board itself for a Google search and Good Luck...
Thanks. I regularly repair all appliances, and furnaces, and familiar with most. It wound up being a bad board. I replaced some components, and have a back up now.
Great educational video Alvin. Thank you. Any idea why I don't see gas flames above the hot water heater and inside the gas heater furnace? These two units are collected in the basement. Gas stove in the kitchen works fine. both units were working fine but all of sudden seems like gas supply to these units is cut off. Thank you.
+jyprkh Since both units are effected then it could be that the gas was turned off in the neighborhood which caused the pilots to go out on both. This is where I would start the water heater will usually have instructions for lighting the pilot. However if what I'm saying is true then you could have air in the lines as well so getting the air out of a line by purging it out through a pilot orifice can take forever. You might can report a problem to your gas company and they will come out for free to light your pilot. But that probably depends on your supplier. I don't feel comfortable telling a homeowner how to purge the air out of gas lines as it does have some danger.
+Alvin Shepherd As far as your furnace goes it could be the same thing after 3 or 4 tries with no ignition your furnace will lock out. You may try resetting the furnace a few times to see if gas will start to flow and ignite. There should be a power switch located near your furnace unless your panel box is within sight These switches will look like a light switch. Which I have seen turned off inadvertently as well in the past. Anyway If your furnace has a lockout code on the circuit board then this would be my best guess again is air in the line. Since it affecting both heaters.
+Alvin Shepherd Lastly there can also be pressure problems that a stove may not be effected by your home will have a pressure regulator at the meter but you will need special tools to determine this so I would call the gas company if you find out that you are indeed getting gas to the water heater but that it is not staying lit.
First off all, a MILLION THANKS for your time and sharing your insight into the issue, tips, suggestions, and cautions. You really have thought through my issue and I appreciate it a lot. I have noticed that the gas comp has been doing work in the last few days about 1/2 mile down the street. Unfortunately they are closed today but will call them first thing in the morning.
+Alvin Shepherd You are correct, there is a power switch but that wasn't turned off inadvertently. Yes, I saw one LED flash (quick flash) when I looked through the little eye piece and I am working on finding out the code/error etc. I am very hopeful that it is just a matter of releasing the air in the line with the help of the gas comp.
Loved your methodical approach to inducing the furnace operation. I just installed a new goodman 95% efficient and I can't get the inducer motor to stay on for more than 5 seconds. I converted it to propane and have the valve screws 2-1/2 times around open. The condensate line is connected and primed with water.. any thoughts of why an new unit won't start?
If the Inducer motor is shutting down. In all likelyhood the pressure switch is not proving and it is locking itself out. In a 90% and higher furnace there are lots of things to cause this. They are very sensitive to unburned gas for one and since you have converted it I would start there. You need to set the gas pressure with a manometer. There is a port located on the gas valve to do this you should be able to find a good video on RUclips describing this procedure. Once you have done that make sure you are not trapping condensation check the hoses especially the pressure switch hose for moisture but also pull the drain hose off the inducer to see if it is filling up with water. If it is then double check to make sure all those hoses have been installed in the correct position. The hose locations change according to how the furnace is installed so go through the installation instructions carefully to ensure they are in the right place for your install.Hope this helps but unless you did this job yourself I'd tell the installer to get his ass back out there :-)
You explain very well, and I learn a lot from your video. However, it cuts off near the end. Do you have another video follow up this one? I would like to watch the next one. Thank you very much!
Van, I have not made another Heating video. I've wanted to do another one which will discuss other problems and will try to get one out before the new year. Please check back after Christmas as this has been one of my more popular videos. Thanks
Hey thank you so much for this extremely thorough and informative video. You took your time out to do this and it has helped me 1000 fold. Thank you sir.
Hey, great video and very informative! I have a weathermaker 8000 that occasionally cuts out. It usually works fine, but sometimes it will light, work for 20 seconds or so, and then the flames go out. It usually tries again immediately to light and does the same thing. It'll do that a few times before quitting totally. Usually turning off the thermostat, power cycling the furnace, and then turning the thermostat back on makes it work. Any ideas? I'm wondering if it is a bad board but I'm not sure
You should clean the flame sensor regardless, if that doesn't help try to get a diagnostics code to narrow the problem down. It could possibly be a fault in the circuit board some of the large standoff resistors get very hot as a result they can cause the solder joint to become weak. If you can't find the problem within the diagnostic codes with nothing stored then remove the circuit board carefully and do a detailed inspection of all the solder joints on the back of the board paying particular attention to anything that looks like it has a ring around the post. Sometimes relays can do this as well. You may try resoldering the board if you're willing to do that give it a shot, Good luck...
Thanks for the ideas. I cleaned the sensor last night and it has been running alright since then. Hopefully that is it because I'm not sure I trust myself to solder the board!
If this is a 90% furnace the condensate pump which pumps the water out of the unit should have two small wires with wire nuts attached to a small thermostat like wires. Try connecting the two wires that run into the furnace together and see if that works. The furnace does not have an error code and those two wires are a safety shut off. They are low voltage so they are not dangerous but dont strip the wires in your mouth.
Also if that is your problem then the outside condensate drain hose is probably frozen? How Cold is it there? Anyway that maybe your problem, it could be frozen is so you need to route that hose so that all the water can drain out after it exits your house walls.
If you are considering a wall unit which has a vent, they're great and need no power to operate. Any of the powerless heaters with a vent are good, but personally I do not care for the odor of the ventless units.
The problem of blow cold air is happened only after several days it is functioning properly. My furnace is Trane XB80 without a little window, so I could not see what code. After removing panels, there is a safety switch shuts off power, put them back, the burner running and it works good. When it blows cool air, the burner is not running at all. Thank you.
Yeah, I'm afraid so. I purchased a 10,000 BTU model / Cozy World off Amazon which used Natural Gas and had to return it. I know I wouldn't buy another one. I'd get something which has a vent flue for the exhaust gases...and that required no power. Floor Models like the old one I had when I was a kid can do a small house, but it would depend on your climate and sq. footage.Thanks for Posting
great site! I have a15yr. arco air 90+works fine however it makes a motor sound. runs for 15 seconds stops and repetesthe same. disconnected exhaust fan and problemstill continues. please help.thanks
I have a Ruud Silhouette II. Most of the times it will not start heating until we tap the vacuum switch. After tapping the vacuum switch then it kicks on the inducer. What fix do you recommend? It is really bad cause it will turn off in the middle of the night and not turn back on. Thankfully i live in Texas where it does not get really cold at night, but still i would like to try a DIY fix if I can.
Great video. I have a trane XB80. The start-up sequence goes all the up to the point of lighting the main burners, but they don't light and I don't smell any gas. I do get 27V coming from the curcuit board across the valve, but no main burner fire. I've done all the other basic stuff, but no luck. First time to fire the furnace this year. San Antonio, Texas. Any help would be appreciated.
Well, as a technician I would loosen the union and listen for gas flow and the rotten egg odor then tighten it back up. If you have good voltage at the valve when it is calling for gas then the problem is in the valve check this video on testing a valve How to test the gas valve on a gas furnace with an ohmmeter now there is such a thing as ghost voltage. If it appears to have the correct voltage but when the load is actually applied such as the valve the voltage goes away. This is caused by a weak circuit most suspect would be the thernostat for this. Simply jump R to W to go around the thermostat if you are looking for ghost voltage until you find the culprit.
I also found once where bees had gotten into the burner manifold orifices and clogged up the gas flow. If your furnace is in the attic and you have gas at the union you might try inspecting the manifold orifices just to make sure.
Generally, if you have gas flowing through to your valve and it's getting 25-29v but still not opening it's the gas valve. Makes sure it's getting voltage everytime.
So many of these go without telling what actually fixed it in the end, so here goes. I ended up making two jumpers that I could use to tap into the 24V supply coming from the units 120V to 24V transformer. I applied that to the gas valve's solenoid. At first no gas flow, but after a little persuading (ie lite tapping) I heard the gas flowing. I removed my jumpers and let the unit go through its start-up cycle and hallelujah it fired right up! So it appears it was a sticking gas valve. The unit is 10 years old, and it looks like the folks that installed the unit did not put in the normal "low point" in the gas plumbing to catch debris and maybe this is causing the valve to stick following a long period of inactivity. To be safe and prepared for trouble free operation next season, I ordered an upgraded valve and will correct the plumbing install when the weather warms which doesn't take too long here in San Antonio typically.
The pressure switch in my furnace had failed and needed to be replaced, this had caused the issue of the burners lighting up and shutting off after a few seconds. Once this was replaced by a professional, it is working fine now.
I recommend this one Williams 30,000 Btu/hr Direct-Vent Furnace Natural Gas with Wall or Cabinet-Mounted sold at Home Depot for about 600.00 It cost more but if you're using it to heat the house it is going to be better.
Alvin awesome video. super informative. I have an issue with my unit. the igniter goes on and off for times and no gas goes thru the unit. I then turn the entire unit off and on again two times and after the second time the unit will ignite and the gas will run through it and heat my home until desired temperature is reached. when my home drops in temperature again and the unit needs to run it have to turn the unit on and off again by hand. I hope I gave you enough info to have an idea on what may be my issue but if not I can provide more. I have a arcoaire brand unit. I sometimes get a 6+1 led status code. which is tied to ignition lockout.
+dannyny Now there are a few things it could be. It could be that the gas valve is not opening properly. Also it could be a dirty flame sensor which doesn't always allow the unit to come on. I would go ahead and clean the flame sensor just take a pencil eraser and clean off any oxidation that might be on it so you can rule that out. If you're still having problems try to watch it to see what its doing. Does it really try to ignite the flame but just no gas if so you need to be looking at the voltage at the gas valve when it is attempting the gas. Are you getting the correct voltage 24vlts AC at the valve. If not then you should disconnect one of the leads probably marked MV on the valve and then check it again with the lead off ( The voltage is applied to the valve after the igniter has been glowing for about 30 secs) if you had low voltage before do you have low voltage now? If not then its the gas valve it has a bad coil with low resistance. Change the valve. If you have low voltage with the wire off but good voltage at C and W on the main circuit board then the problem is in the circuit board. As long as all your wire connections are good. You should also check the High Limit voltage as well and any roll out switches to ensure they are all sending good voltage through them as well. Hope this helps...
+Alvin Shepherd thank you for the reply. I understand the first half of your reply but I'm not too handy to deal with electrical. I do know the igniter strip lights up and waits for the gas to shoot out but it does not then the igniter goes off and tries again. after 4 tried the system shuts itself down. I read thru the troubleshooting label and it mentions one of the wires has to be grounded to the sheet metal of the body of the unit itself. I took the wire off the fuel rail? and screwed it into the sheet metal and it seems to help as it comes on after its 3 attempt now instead of restarting the unit and trying 2 to 3 times. if you suggest the gas fuel rail injectors are dirty I can try to take it apart and clean them? my father installed this unit one day with his friend it was kinda like a diy install. he also cleaned the flame sensor with a metal pad. looks pretty clean. any feedback and help is greatly appreciated!
+dannyny Are you saying that you took the wire off the flame sensor and screwed it to the sheet metal. If so this has to be removed asap. What you are doing is wiring around a safety which prevents the furnace from operating unsafely. The flame sensor detects that the burners are all lit and that the gas is burning in the right place. Imagine what would happen if the flame was lit but was just burning inside the furnace compartment instead of going into the heat exchanger. Danny I enjoy helping people but there comes a time when you are better off leaving this to a professional. If you are not comfortable with electricity or do not own a volt meter there is simply no way you are going to be able to diagnose the problem with your furnace.
+Alvin Shepherd i did not place the wire from the igniter that has two white wires coming from it. the wire i placed on the sheet metal is from the control gas valve it is the green and yellow wire. on the diagnosis troubleshoot sheet it stated it MUST be grounded to the sheet metal. I did call professional help but he came saw the machine was new and said looks fine and left. it has been running for 3 years but last season it started failing. thank you again for the help. it is super informative as I said before.
Ok, It is difficult to understand what you are talking about when you say you took a wire off and connected it to the sheet metal. If you are talking about a green and yellow wire then that will just be a ground wire. No problem. But it still doesn't negate the fact that in order to test to find out which one of the components are failing you are going to need to have a volt meter. You are going to have to know how much voltage the gas valve is getting. It should be 24vlts AC but if it is not at least like 22 or so then you are going to need to determine where you are losing the voltage. This cannot be done without a volt meter.
We just bought a home in Indiana a few weeks ago. It has a TAPPAN Model # L1RC 080D-16B furnace 2005 or 2006. Last week the furnace would turn on, but stopped igniting and blowing hot air. The flashing light indicator showed it as a pressure switch open w/ inducer running error. Each time my husband would jiggle the cable it would work again. So he replaced the insulated terminal and we didn't have any more problems for about a week. Then of course at 3 am today (Christmas morning) is happened again. We unfortunately don't have the connections we had back in Michigan and would be happy to get any suggestions.
One thing I'd check on a cold holiday night is to see if there could possibly be water in the vacuum hose going to the pressure switch. Now I do not recommend sucking or blowing on the pressure switch. They are made for very low pressures and it could damage it if it is not already bad. If you have a volt meter you can check to see if you are getting voltage across the pressure switch. with one lead to ground you should have 24 vlts. on both sides if the switch is closing. About the water issue if you do find water in the tubing get it out and remove the pressure switch and lightly tap on it to see if you can remove any water from it too. This may not be a lasting repair but at least it could get you to when the supply houses open...Good Luck
Part 2 Also If the vacuum switch is getting water 1)There could be an issue with the placement of the switch or need a modification as some switches have a vent hole which continually pulls in a slight amount of air to prevent a moisture problem.If you find water in the hose or switch I will go into more detail of how to repair this issue.
Would a bad condensate pump cause the same problem? We noticed there's water in this tube going from the pump and furnace to the sewer pipe. It doesn't sound like this little guy is running. Looks like it's a "Little Giant" pump.
We didn't noticed any water in the lines coming from the pressure switch. My husband said he'd check the voltage when he gets home from work. I can't tell you how absolutely gratefully and pleasantly surprised we were to see you respond to our current woes. Thank you from Indiana!
Dawn Vanneste It seems so sporadic. When the furnace wouldn't blow and we would jiggle to connector going to the pressure switch, it would start. Now that doesn't seem to be working anymore. This last time I couldn't get it to start until I tapped the pressure switch itself gently. Any tips, ideas, and suggestions are so greatly appreciated.
Thank you for the great video. I am getting the 3 fast 3 slow blink code on my Carrier furnace. Flame igniter is new. Flame rod looks pretty clean. Inducer turns on. The furnace will run for approximately 2-4 minutes and will then stop the gas/heat while the blower continues to run a few minutes while emitting the 3 fast 3 slow code. It then recycles. Air filter was clean but still swapped it out with a cheap commercial style filter with barely any filter ability and the furnace will run. According to the code it can be many things. Seems to be an air flow issue of some sort. The furnace is 16 years old now. Do you think it could be the blower motor not up to "speed" anymore? Any tips or advice would be greatly appreciated. Thanks.
Check your High Limit Switch and also the Roll Out Switches to ensure they are all in the closed position. Using a volt meter with one lead connected to ground you should get 24 vlts. A/C on each side of the switches if it is closed and only on one side if it is open. Sometimes these switches are ran in series so some may have no voltage also. Hope that Helps....
Hey Alvin. Thanks for the video. I was hoping you could give me some advice. We have a York furnace and we lose the flame if it has to run too long. Most of the time you wouldn't even notice. But when it gets too cold outside (and therefore inside) the furnace will lose it's flame but the fan keeps going. Once that happens of course we get no more heat just a blowing fan and a very cold house in the morning. As long as the temperature can get up to where the thermostat is set within a short period everything works. If I set the thermostat 2 degrees higher than the room temp it loses it's flame before it can get there I remember having this problem in the past and I believe they replaced the control circuit card. Does that sound like the likely culprit to you?
It sounds like your system is either locking out after a few tried attempts to re-fire or you have a high limit that is over heating. If it is the high limit then it will shut the gas valve off and keep the blower fan running. This can be caused by low air flow. That can be from allot of factors like a clogged air filter, dirty blower wheel, covered up return registers etc. You can tell if the unit is starving for air by running the unit with the blower door off and then use it to cover the opening if the door is slamming up against the furnace then the problem is before the blower. If not the problem maybe in the blower wheel or after it. You may want to check the evaporator coil to see if the coils are covered with dirt as well. You could also have a bad circuit board if you cant find any problems with air flow. Remove the board and examine it very carefully to see if you can detect any gaps in the solder connections. These can be difficult to see but ussally appear as a ring around the pins. Hope this helps...
I had a 10 yr old York furnace up in the ceiling, It stop working and I just replace the surface ignitor with a new I put it on and I saw its firing flames but it didn't blow any air at all. I did check the flashing red which is 4 blinks which the diagnostics says High aux. or spill limit switch open. Could you explain more on this, I really appreciate your output on this. Thanks
They are refering to the parts I call the High Limit and the flame roll out switch in the video. They are both wired in series the roll out has a reset button. You can check to see if one of them is open by using a volt meter and placing one lead on the unpainted metal in the burner section then putting the other lead on one side of the switch then the other. Both sides should show power 24 vlts. if the switch is closed. If only one side shows power then the switch is open. The High Limit is auto reset so if it is open and the furnace is not hot then it is bad.
Alvin Shepherd Thanks Alvin for the prompt reply. I'll give a try on your advise, also I forget to mention that before it stop working i smell like a burned plastic kind of thing on the duct that when found out it stop working, Im afraid it might be the motor of the blower or something else.
The system operates off the principle of "flame rectification" that is a flames ability to "rectify" an AC signal to a DC signal, thus proving a flame exists, otherwise no DC signal will be sensed . A flame sensor is a metal rod that receives a DC signal through the flame, sent via the igniter. The flame is an electrical conductor, but more relevant it "rectifies" an AC signal to a DC signal, the "flame sensor" is a rod that "senses"a DC signal. Many units have no flame sensor however they operate alike. Their DC signal is "sensed" via the burner ground which if you notice terminates on the ignition module on ground or burner ground. The DC signal is mere millivolts as the flame is a poor conductor, it does not take much to interrupt the DC signal returning"proving" the DC signal exists thus proving the flame exits. 0000 steel wool is best to clean a flame rod/ flame sensor. Most units today have a diagnostic light that will be steady on or off or flashing in a sequence that indicates a specific fault ,a legend on the blower door tells you the specific error/fault. If can be a flame sensing issue ,however more commonly found is the induced draft proving switch is the problem, it has a rubber hose that attaches to the induced draft housing that senses the inducers operation . The pressure switch closes ,telling the ignition module that the induced draft is operating. The barbed nipple /port on the induced draft housingwhere the pressure switch's hose attaches will clog with carbon about every 2 years on most units, it is tough to clear, I use a paper clip unfolded and make sure the carbon is cleared by hearing the clip touch the induced drafts blower wheel, its easy to trick yourself thinking its cleared.
Hi thank you for willing to help a little bit. The problem I'm havingis, every now and the, while unit is off. The unit sounds like it's cycling on for about a min then off for about a min. It does this for a little while the. Will stop. Nothing g I do seems to fix it or make it stop
It sounds like your furnace blower motor to me. I have seen blower motors cycle On and Off when they are located inside a hot attic when the temperature gets up to around 120 degrees F. You may try adjusting the Fan Limit Switch on your furnace the middle pin controls the Fan On position and by turning this up it will not come on until the unit gets to a higher temp.
I am having the most frustrating experience trying to set my White Rodgers fan limit control switch. As you may know the limit dial has two pointers, so if you could please PLEASE tell me where to go from there, I'd really appreciate it.
+Ta'Shawnda Price Ok if you look on the dial you will see two which are adjustable and one which is fixed. The fixed pointer is the limit this is the safety which will kill power to the gas valve in the event of an overheating condition. The next one closest to the fixed pointer is the Fan On switch that turns the fan on. The last one is the fan off. Now here's the kicker, if you are having a problem where you cannot get the fan to stay on they have a fan limit model that has what they call a heater. There are two more wires coming off the back and those tie into the gas valve (Low Voltage only circuit) Also make sure you dont get any of these wires confused as you can do serious damage by connecting a low voltage circuit on the limit into the high voltage fan circuit. Anyway the fan heater is designed to prevent the fan from short cycling so that anytime the heat circuit is energized the fan will stay on. Yeah I know this bites, Good luck...
+Ta'Shawnda Price Now normally the Fan off position should be set around 110F unless your furnace is located in the attic ( in that case you can actually have the fan come on in the summer you may want it higher) But generally around 110F then the Fan On should be set up around 140F or even 160F but not any higher. If you are having a problem with the fan going on and off even with the fan limit set at 160 then you're going to need a new one and you may want to go ahead and get the one with the heater cause otherwise you're taking a chance that it will do the same thing. Good Luck
My Bryant 90 plus is 20 years old stoped heating. I find that by flipping the power switch (The one on the side of the heater that looks like a light switch) off then back on, will usually get it running again. If not. Then I'll bang on the side by the switch a few time and It'll be up and running again for a day or two. What needs to be replaced. The power switch?
Maybe, what you really need is a volt meter. They are cheap and are great tools if nothing more than sorting out good batteries from bad ones. The problem is that by shutting off the power to the furnace that will reset any lock out that the furnace was in. It still wouldn't hurt to rule out the power switch just the basic light switch only cost about $1 dollar. But inside the furnace on the Circuit board there is an Led light when your furnace loses power that light will go out. If you find that the light is out until you knock on the switch then I would say yes you have a bad switch but if that light inside the furnace is blinking then you need to watch the light to see if it has short and long flashes there will be a pause and then it will repeat also there will be a diagnostic code usually on the blower compartment door on your furnace that will help to diagnose the fault. Hope that helps...
I have a New Yorker oil furnace. It runs fine most of the time. Every so often the fan stops. If I go down and tap the fan box, it kicks back on. Needless to say if we are not around when this stops running it tends to get quite cold. Any ideas?
I don't know that much about oil furnaces as they are rarely used in the South. However it sounds like you may have a sticky Fan Limit switch. This switch has a bi-metal spring which extends inside the heat exchanger and as the temperature rises the spring turns a dial with 3 tabs two of which can be adjusted. Sometimes adjusting the Fan On and Fan Off tabs can correct the problem you're speaking of however most of the time you should replace this part. If you will watch this dial as the heat exchanger heats up it should slowly and consistently turn if it sticks, then when it finally lets go the High Limit part of this dial (The 3rd tab) will cause the fuel to stop. So that's where I'd start.
I have a goodman furnace,it lights sometimes then I just here a click and blower but won't light,I changed the flame sensor and cleaned out trap from induces still same.
Without removing the furnace door look through the little window on the blower door there should be a error code led light. Ussaully on the blower door there will be a diagnostic code what error code are they telling you?
My furnace ignited and burn 3 seconds and turn off it repeats the cycle 3 time then fan turn on nonstop with error 2 red flashes. Have Changed flame sensor and pressure switch but problem stills the same. What’s next troubleshooting?
The vacuum pressure switch needs to have a good hose with no holes I have seen rodents chew on the hose making a hole in it. Also the port that the hose connects to on the induced draft motor needs to be clear you can take a Jim Clip and push the end down inside the port to make sure it is clear of debris. Last you need to make sure that the main circuit board is grounded if not it can't get the proper signal from the flame sensor. Hope that helps.
The heat unit from my business is a carrier one and the blower works and it sparks to try to turn on but looks like the flames won't come on do you know how to looking for that part or how to change looks like the gas is no coming true
Some older Carrier units have what I call a 3 wire pilot. The spark ignition device ignites a pilot and has a yellow, green, and white wires coming out of the bottom of it. When the unit calls for heat this device ignites a pilot then after a few moments it allows the main gas valve to receive power and gas to flow. Is this the type system you have. If so the problem is usually within the device itself, usually the problem comes in where the device cannot prove the pilot is lit.
We have been setting our thermostat at 71 and the heater wont kick on unless I turn the thermostat off and then on. It will kick the furnace on but won't stay on.
The furnace is locking out. After 3 or 4 attempts to ignite the gas the furnace will lock out. When you turn the thermostat down on some units the furnace will reattempt to work. You need to try looking in the window on the blower door to determine the diagnostic code this is in the video Thanks
I opened it up. Dusted it out. The led lights establish there are no problems. And the thermostat is at 70 and it reads 70. I don't know why it locked out last night. As I said this morning, I had it set at 71 and woke up to lower 60's until I turned it off and then back on. And thank you for your help.
Does the furnace information decals show that the circuit board has any diagnostic codes indications? Not all do but if it does it should list the error codes probably on the furnace door. If you do have error codes with no window. Temporarily tape the door switch closed so you can get the door off without it losing its history lockout condition and when it fails again check to see what the error code is.
HI i got a question for whoever knows the correct answer..... I recently came across a new pool heater in Canada and there is no shut off going into the ground after the meter and there is also no shutoff behind the shed where the GASTITE goes in but there is one shutoff connected to the valve train before the gas valve. Does anyone know if you need those extra shutoffs and if so what code is it in the CSA B149.10 code book thanks
I have a four year old 90% efficient York heater in my attic. The heat goes on at the right time but then shuts off while the fan keeps running for as long as it takes me to get up and turn the thermostat down (sometimes half an hour). I just had a service man here who couldn't fix it. I'd like to get it fixed while it is still under warranty. This problem has happened since it was new. Any suggestions.
90% Furnaces are also called condensing furnaces. They make water from the humidity in the indoor air. That water can collect in the vent flue if the venting is not ran properly. The vent flue can either be ran to drain outside or back into the furnace but it cannot have sags where it will collect water as it goes outside the house. Also these furnaces can be sensitive to the type of intake air you have. If your unit has an exhaust and outside air intake check to see how closely they were installed at least 12 inches and the intake flue should never be installed above the exhaust flue as it will pull the steam condensation gases of the exhaust. These gases will cause the furnace to malfunction. Hope that helps. Another thing they make water and that water drains sometimes a condensate pump is used to pump that water out. If the condensate drain is holding water outside in the winter it can freeze. Here you will ussually notice that the condensate pump is full of water and running non-stop. If this happen you can ussaully cut the discharge tubing near the house or reroute that tubing so that it will not hold water. Check those out and let me know....Good Luck
thanks for your response. there is a 3/4 inch pvc pipe that gravity feeds the condensate to the outside. when the heater is on, water drips out of it. I'll see if I can get more slope on it. you might like my video from Nat Geo ' Chile, great prison escape" .www.amazon.com/dp/B00AUN9RHY thanks again. Tom
The vent flue is a 2 inch PVC pipe which vents the exhaust gases from your furnace to the outside of the house. There is high moisture in these gases which create condensation. If this piping is ran in such a way (dips and slopes) it can hold moisture these furnaces are very sensitive to even a small amount of pooling water. On your condensate drain I was referring to the discharge tubing which is a 3/8" Vinyl tube that comes off your condensate pump and runs outside those can freeze up outside in cold weather so you might check that too.
My furnace works but is acting up.. There's a delay after you here the click from the thermostat. The furnace starts humming and kinda buzzing before it actually ignites.. Any thoughts?
My guess would be a buzzing relay. But you might try carefully putting your hand on some of the components inside the furnace while this is happening. Being careful not to touch any wire connections and get shocked. The part which is buzzing should easily be identified that way. Sometimes low voltage can also cause this so check your voltage without a call for heat and then with it calling. If the voltage is dropping below 24vlts then you may have a wire shorting out where the insulation has become damaged or a coil going bad. You can isolate electrical problems like this by jumping out the connections at the furnace R to W at the furnace calls for heat without the thermostat or thermostat wire involved, Same thing at the Thermostat takes out the thermostat but not the thermostat wire etc, Hope this helps...
I am having trouble with my propane furnace it is a American Standard new in 2014. It has just barely started acting up. Right as the blower kicks on it has a sputtering/ rattling sound for about 2 seconds once the blower is on there is no noise. The rattle/sputter is not very loud but it is there. It heats good and everything seems to be working fine. For the past three years there has been no noise at all and this is something new. I want to know if this is something like a cracked heat exchanger and should I worry about leaking harmful fumes any help would be greatly appreciated.
Should my ingniter fire stay lit at all times near the burners??..and my pilot light flame is bigger than it was before I had some repairs is that normal???
Lonnie about 1990 furnaces replaced standing pilots with ignitors. So if your funace is made after 1990 I doubt it has a pilot unless it has an intermittently lit pilot which was around for about another 10 years. Now you are saying that the pilot flame is staying lit all the time and that it is bigger than before. It sounds like you have an older furnace and yes these stay lit so that they can light the main burner when your thermostat calls for heat. If the flame is bigger than it use to be it maybe that the repairman cleaned the pilot assembly or he could have even used something to enlarge the pilot orifice. I dont recommend doing that because the pilot orifice hole is so tiny that even a sewing needle hole would be much too large. So he may have done that. If the pilot flame is more like a torch now than a little pilot flame then I would say he definitely did do the dirty deed. But if your furnace is that old and the pilot is having problems staying lit then I would be looking more closely into a new furnace. Chances are you have a crack in your heat exchanger which is blowing out your pilot flame so it might be time to get a new furnace. Only an honest on sight technician can determine for sure.
If the inducer cycles, ignitor comes on, the gas valve clicks (24v verified), this says all the pressure switches and sensors are working -correct? The flame sensor circuit is not even active yet -correct? Bad flame sensors will only show up after flame should be detected -correct? I have all of the above, with no flame. Additionally I have a modulating gas valve (97% furnace) with an additional stepper motor in the valve that is not turning (took the cover off and made an inspection hole to observe the stepper shaft end). Bad Valve? Board? or something else? Yes, I paid my bill, and there is presence of gas at the valve and other appliances work. Thanks. It's also giving a 7 code lockout -no flame detected.
salvor1, your comment went into spam for some reason so I'm just now seeing your question. All your statements are correct the furnace igniter will not get power until all the roll outs, inducer motor, pressure switch have been proven. And the flame sensor can not be a problem unless you have a flame however that is still what shuts the equipment back down. It sounds like you have a bad gas valve just make sure that you are in fact getting gas and power to the valve. Code requires that every appliance have it's own gas shutoff within reach of the equipment, also there are tap screws mounted onto the control valve for taking pressure test so that's a good place to ensure you are getting gas. Just loosen the tap screw with an allen wrench til you hear or smell gas. There are two tap screws one on the input side of the valve one on the output side. The pressure will be higher on the input side than the output. These taps are there to check gas pressure and to make adjustments using a manometer the output side of the valve should have 3.5 inches of water column. But as long as you are getting gas flow it should lite off. The only case I have ever seen where none of the above helped was when some dirt dabbers wasp made their home in the gas manifold and plugged up the gas orifices.
You are very knowledgeable, but this isn't an effective 'troubleshooting' process. This is what I'd like to see: 1: You turn up the thermostat and nothing happens. Steps. Check A, B, C. 2: Fan starts, but gas doesn't ignite. Steps, A, B, C. 3: Fan starts, ignites, but turns off right away, Steps: A,B,C. You need to give a process of elimination. I can tell you know a lot of stuff, but you are kind of all over the map. Simplify the process for those of us who don't know. thanks for the information. Appreciated.
I just replaced my gas value and the ignitor is turning red but doesn't want to start still, did start when it wanted by not anymore, do know what the problem could be, could use your help thank you
+Andrew Ramos check the voltage getting to your ignitor some boards can have problems where they are giving your igniter low voltage. Another thing I have seen also is that the ignitor can be out of position. Lastly you can have an ignitor where the resistance has increased so that it no longer has sufficient current flowing through it. Hence a glow coil should glow very brightly before the gas valve opens it should be a bright orange or yellow not red. Of course a ohmmeter would be a better way to check it along with an internet search for the proper resistance measurement on your part number.
My thinking would be first to check if there might be a piece of paper caught in the blower wheel. Make sure the furnace has no power and turn the blower wheel slowly while checking for debris with a flashlight.
@@crand20033 Okay an Intake tube? There are two motors inside the Furnace the Blower motor is the large motor behind the bottom door. The Induced draft motor is a small motor that exhaust the flue gases from the heat exchanger. When you are speaking of a tube attached you must be referring to the inducer motor. If that motor is clicking or ticking its probably the bearings so I would recommend replacing the inducer assembly. You can do a part search using the model number + inducer assembly. Hope that helps...
@@AlvinShepherd No, when I said tube I mean the large foot and a half diameter duct. that goes to the bottom area where the blower motor is. I would have to remove it to see the blower motor unless I remove the whole blower assembly from the furnace.
Mysterious. the LED light on the control panel shut off and I thought the thing had fried. Took it off and checked the back and it looked like new. I made sure all the connections were tight and decided to reset the roll out switch. So I don't know if it was one of the connections or the reset that did the trick, but when I powered up and pushed the door switch, the LED came on and the furnace is working fine, Can a tripped roll out cause power to the board to be cut off?
No, that would only prevent the Gas Valve from getting power and gas flow. It's possible you had a lock out condition after 3 tries and you simply reset the board. Some of these LED bulbs are in a very bad spot to see them so it's also possible it could have been out of view or behind some wires as well.
If you know for sure the light was out, then it's also possible that when you reinstalled the board you may have tightened up a loose connection. But I've never seen a rollout wired up to kill power to the control board.
I had an HVAC guy install the gas and propane conversion kit to a new Whirlpool furnace for my cabin. I wired it and tried to get it going, but I'm getting a 2 flash error code. What happens is the call for heat is made, the blower starts up, the glow plugs are activated, but the gas valve doesn't open. I hear a clicking sound, but no gas is ignited. The HVAC guy thought it was the main board, which I replaced with a new one, but it didn't make any difference. I'm thinking it might be the gas valve? Any thoughts/ help on what I should do? I'm thinking maybe I can jump the valve with 24 v and see if it opens?
Yeah sounds like a good plan. Sounds like the gas valve to me as well. You should hear the gas flowing after the click. This is a good way to test it but dont rewire it to run even if it works as you have no safety running like that.
No. The circuit board has to prove that the pressure switch is opening and closing. So they ussually will start the inducer motor then shut it back off momentarily to prove that the switch is closing and opening before attempting to go to the ignitor.
Your furnace is "Locking Out", this can be caused by several different problems. But there should be an easy way to isolate where the problem is. On the furnace door there is a little window. Next time the furnace acts up look through the window and see what code it is given you. It is sometimes like morse code with long and short blinks with a pause between. Then on the door ussaully there will be a diagnostic error code label. Dont take the door off until you know what the error code is or it will reset itself and you'll have to start over. Once you know what the code is check back with me and I can tell you more about how to diagnose the problem as these codes may only get you into the circuit that the problem is in.
Alvin Shepherd I need to know what the code is indicating not how many short and long blinks the light has. As there are so many circuit board models I could never recall all those.
+madonna martin There is a flame spreader bar which is integrated into the burner. It is the flat part of the burner where one burner is in close alignment of the next. What can happen sometimes is that the A/C coil usually located above the furnace will leak and cause water to drip inside the furnace during the summer. This water will cause rust in the burner spreader bar. You will need to remove the burners and take a very small screwdriver and clean out this area especially along the most forward edge of the burner then re-install the burners. This should fix your problem....
It's 50 degrees here so o don't think its frozen,I flushed it all the way out there was no return water coming back.those to wires I'm not aware of this where is it located?
OK if this is a 90% furnace it makes condensation. You mentioned cleaning out some water. So I'm assuming this water runs into a small pump. Many times these pumps go out or clog up. Do you have a condensate pump? Is it running constantly? Is it full of water?
+Scott Lucken Most Blower Motors found in furnaces are PSC (Permanent Split Capacitor) Motors and will have a Run Capacitor which is connected on two wires (usually brown wires) I would start here. A bad capacitor will most of the time be slightly bulging especially if you take a visual of the two top wire connectors they should be in perfect alignment from a side view and they will be facing away from each other if it is bad. The capacitor should always be replaced anytime a motor is changed and are sized in (Mfd) Microfareds and voltage. Of course you should check the bearings for free movement this can be done just by spinning the blower wheel by hand it should spin easily. However motors are going more and more to sealed bearings so those cannot be lubed. If you have one which can you can inspect the back edge of the motor and there will be a fill port which should have a small cap that can be removed. A zoom spout oil works well to lube the bearings. But there is a port on each end and you cant get to the one near the blower wheel without pulling the motor assembly from the furnace. As far as the circuit board I doubt that is the problem seeing that is you give it a spin it runs OK but you can check the voltage while the motor is under a load to ensure it is getting a good connection if everything else checks out. Hey and be careful...
I hope my fellow HVAC techs are ready for the ultra low nox furnace that will be out in the market in your area soon they are and mandated to require all over California
I stand corrected, I knew that I just said it wrong. By the way I found a flame sensor once that had low amps. Someone had installed a new circuit board and did not connect the ground lead to the board.
+Lisa Stein No, the only way a dirty filter could have any effect on causing a problem is if the filter was so clogged that the furnace kept over heating over and over until it made the high limit switch go out. At that point the unit will no longer call for heat and most will cause the blower motor to run continuously. You need to watch the unit to see what it is doing. Does the inducer motor start up? If not then this will likely be a problem in either the high limit or roll out switches. If the inducer starts up then you rule out those and go to the vacuum pressure switch or igniter next. But if you watched my video then the Diagnostic code I spoke of will help narrow the problem down for you the most. Good Luck
Its getting below zero and my furnace is being a pain. WHen i first started it a couple weeks ago is coded pressure switch stuck open ( 3 red lights ). does that every year after sitting idle for a few months. But its NOT coding red this time. Green light says normal. Filter is cleaned. I turned breaker off then back on to reset. I turned thermostat to lowest point, then higher. Furnace stays quiet. Not even trying to start up. Its an old mercury thermostat so no battery to change. The wire from thermostat to furnace was replaced by a plumber 2.5 years ago..... thoughts?
@@AlvinShepherd The big black thing> Its been running for 2 weeks, no issue. Then just nothing a day ago although it has the green light which says its ok. How do i make it spin? My thermostat is 20 years old. I'm nervous about trying to replace it on my own, lol
My furnace flame lights up and stays on. However it is still blowing cold air out. Thermostat fan is set for Auto, air filter has been changed. Any advice?
Call Fox 5 News. If you have a fire and air blowing across it unless your duct work has come apart and blowing into an unconditioned space then you it will be hot.
Alvin Shepherd I'd look at my duct work, Do you live in a building where there could be fire dampers installed? Fire dampers can prevent air flow if they fail no air will flow. You say you have air flowing are you sure? What you've described is not possible. Blower Wheels can become so covered in dirt that they will no longer move the air check the blower wheel to see if it is full of debris if so the blower assembly will need to be pulled out and cleaned being careful not to get liquids into the motor. Lastly sit with the furnace for about 10 minutes while it is running, if it is over heating and shuting down and then starts back up then you definitely have a blockage causing the air not to flow.
Alvin Shepherd Hi thanks for the response. Typically what will happen is hot air will blow out for about 5 minutes, then it'll become cold. When I go look at the furnace the flames are still blue but the air coming into the house is still cold.
Alvin Shepherd Hi sir, me again. I just wanted to update you on what happened. I located a large vent like area above my garage door in my hallway that was really dusty on the outside. I took a vacuum hose to it and vacuumed all the dust out. Since then my heater appears to be working correctly *knock on wood*
Sometimes these dusty air vents may have a dirty filter located behind them too. Because some of them (The dusty ones are returns) people will sometimes put filters behind them even when they are not intended for one...Good Luck
I have a Coleman Furnace. When it clicks for the hat to come on, the furnace keeps clicking on and off and then after awhile it will finally come on. And when it starts it makes a loud noise and acts like it doesn't want to stay running. What can be the problem? This makes the third year doing this.
+Peggy Garcia Sounds like a dirty flame sensor Peggy do a search on how to clean your furnace flame sensor I recommend using a pencil eraser to clean it, but don't use sand paper. Sand paper will take off the rust protection and will cause it to fail more often.
My furnace has a Honeywell sv9501 smartvalve and when I went to start my furnace for the first time this year nothing happens when i do the recommended 5 minute "reset" indicated on the sticker. Nothing happens with the thermostat, pilot, or any other parts or motor. Its like nothing is getting power at all. Im going to kick myself for not paying close attention, because last time this happened the repair guy came out and messed around with it for less than 5 minutes and everything was ok......any advice?
First, are you getting an LED error code? If you look through the window in the blower door there should be an LED light blinking. If so check to see what code it is giving you. Second if you have no LED on the main circuit board the circuit board has a fuse check that. Next check your panel box for any tripped breakers. After that you will need a volt meter to make sure you have power coming into the furnace from the house. You should also check to see if you have low voltage on the circuit board R = Power C= Common you are looking for 24 vlt AC. Next take a jumper wire and go from R to W (Heat) with the blower door switch closed this should call for heat if it does the problem is in your thermostat or the t-stat wiring. Let me know...
sir, your quick video was somewhat educational. I live in cold Chicago and recently started having problems with my furnace. After watching your video I was able to get my furnace up in running in about 30 minutes. You just saved me a lot of money and help keep my family warm tonight. For this I thank you very much.
THANK YOU! I was troubleshooting an American Standard Freedom 80 Furnace and your explanation on the flame sensor cleaning fixed our problem and we have heat again. We had two blinking lights which did not really indicate which component was failing and google did not provide much help either. I also appreciated your explanation on the sequence of operations. Good work on this video.
Thanks, Glad I could help. Invoice will follow :-) Joking
Alvin, thanks for posting! My Goodman GMP075-3 would ignite but the blower motor would not come on. Put the thermostat on "fan only" and fan came right on. Checked the LED code, no problems. Came here to RUclips and saw your videos. Finally, took the vaccuum hose off from the pressure switch and inducer motor, blew a good stream of lung power through the hose, put it back on and abra cadabra furnace now works. Thanks for helping out us home owners!
Thanks so much for the video. I was troubleshooting my furnace and your description of the burners coming on and then immediately turning off described my problem perfectly. I pulled the flame sensor. Cleaned it up as you recommended and the unit began operating normally again. No doubt saved me a service call and potential costly repair.
failed to open the lid of the carrier furnace installed in 2003 so unable to take out the sensor
Alan,
That's a lot of great information. It helped me to understand the system better. Thank you for taking the time to create and post it !
Thanks for sharing these videos with us. We really appreciate your time explaining in detail about the components and how they work. Thank you..!!!
well done.I now have a good understanding of how a furnace operates .I laughed like hell when you said that someone had forgotten to remove the plastic from the filter.
A gold mine of info for those with some tools and a bit of experience. Thank you very much !
I was almost going to call repairman but after your video and a no. 2pencil I, no longer had too...thanx again
Thank you so much with you help i was able to fix my furnace and now my family has heat in the house.
AWESOME! I fixed my furnace thanks to your video! Saved me a butt load of money. Thank you for posting the video
What would we do with out people like you! Seriously! Thank you for everything
Thanks for your kind words and glad I could help...
This was an excellent video for a novice (me) lol, I am very mechanically inclined! After watching this video I can confidently troubleshoot a furnace! Thank You great job explaining everything!!!!!!!
+1 for cleaning out the hose connection between the motor and the pressure switch. That's exactly what my problem was and I just fixed it thanks to your video. Saved me money, I'm sure. Last time I had to call someone out, they wanted to sell me a whole new furnace for $5000. Turned out to be a loose wire. Thanks!
Thank you, thank you, thank you...You just saved me a coupla hundred bucks! The tube, which you described may have rust in it was blocking the ignitor from initiating, which in turn prevented the gas from turning on "sequence of operation".
Thanks on the Great Video, I just had to rest my , Rollout Switch, wouldn't have found it without your Video
THANK-YOU!!! what an informative running down of the operation and troubleshooting of a gas furnace.
Thank you for making both of your videos this morning and on the heating side of the system I am currently on the Internet trying to figure out what might possibly be wrong with my Friends heating system he had a problem with the electrical companies connection being loose at the pole we are guessing burn out the circuitboard in the furnace but watching RUclips videos has definitely give me a understanding of how heating and cooling furnaces work I feel if I ever have a problem in the future I could definitely diagnose it I appreciate your time taking to make this video and your other ones
bro u hit it the nail on the head , it was my circuit board, thanks for your response
Elven thank you for being so diligent with helping everyone with their problems. Let me tell you what I have diagnosed thus far to see if you can give me some feedback. All of the steps on my Armstrong air Tech 80 that you have discussed in the video are going correct however it apears that the blower is not spinning up to the "RPMs" "that it should. When I compare this unit in my upstairs to the properly operating one in the basement, it seems to be running much slower. Much more lethargic. I hope that's enough info to give you some direction. Thanx again for all your help.
The Main Blower Motors are called Permanent Split Capacitor motors. Because they have a Run Capacitor which is in line with the motor windings. These capacitors make the motor run more efficiently by making the voltage more constant in Alternating Current however when they get weak or go bad they can cause the motor to run slow or not at all. This is where I would start. There are ways to test the capacitor but it requires a special tool so I would just order a new one because they are only a few bucks. Take a look at your motor and follow the wires coming off the motor two brown wires will go to the run capacitor. Remove it and get the capacitor size such as 5 MFD/370 vlt. , 7.5 MFD/440 vlt. etc. It could be that the motor bearings are causing the motor to bind as well and to not get up to full speed also but this condition will also cause the motor to overheat and shut off after a while. This condition can be checked by simply giving the blower wheel a spin and checking to see if the motor bearings seem to be allowing the wheel to spin freely. What you should not have is a blower wheel which comes to an abrupt stop. Manufacturers have been getting away from motors which have bearings that require maintenance oiling if so the motor will not have oil ports. So generally speaking you will need to replace the motor in a case of bad bearings. Good Luck...
Hi Alvin,
Is it possible for the blower motor to cause the following problem?
I have replaced everything but the two limit switches (rollout and high temp) and I also have not replaced the blower motor (yet). But, my furnace starts (lights) and then goes off after 10 to 30 seconds. I have cleaned the new Flame Sensor with an easer and made sure it was inside the lit flame.
The furnace tries to light twice. The first time the flame starts and then goes out after 10 to 30 seconds. The second time the blower motor starts and then ignitor glows, the flame lights and then gas cuts off as before. The blower motor continues to run for 3 to 7 minutes. at which point it comes to a halt (slows and then stops). I do think the motor needs replace but I don't understand how the flame turning off after 10 to 30 second relates to blower or if it should.
Any suggestions with me helpful.
Roy
RHH1095, If the furnace is firing up then you can rule out having a problem in the roll out switches. The problem sounds like it is in your flame sensor circuit. The circuit board requires a good ground in order for that circuit to work properly make sure your electrical supply ground is connected and that the circuit board is grounded as well as the polarity has not been reversed. The only way your Main blower motor can effect the flame going out is if it is causing the high limit to trip as in not enough air flow or the blower motor shutting down. You should also make sure your high limit is not opening but I doubt that would happen in 10 to 30 seconds after the gas lights. Hope this helps....
RHH1095, I have noticed allot of people get confused with what the Induced draft motor and the Main Blower motor is. I just re-read your message and now I believe you are referring to the Inducer motor. This motor is the one that starts up immediately on a call for heat. The inducer motor can control the gas valve with the vacuum pressure switch but the only way you are going to be able to determine if that is a problem is by the LED diagnostic code. As that could be a momentary problem.
Thank you! Your response has made me trace the terminating point of the flame sensor back to the IFC. (I also replace the IFC board because of burn marks.) The new board does not use the AC-Common wire as the termination point did originally (older furnace). I see now from the IFC manual that the output of the Flame Sensor goes to directly Pin#7 of the nine pin connector. (yes I'm embarrassed but its like asking for driving directions). I believe the behavior of my blower motor just means it needs to be replace (what started this process!). Thanks again.
Thanks for this awesome video. It solved a failure on a night that is forecast to be 17 degrees.
just want to thank you this video just helped me fix my furnace
Cool
Doru, On your furnace sometimes the flame can have trouble spreading across the burners if this seems to be happening on your unit it is probably the reason your having the problem with your furnace. If so remove the burners and on the output side there is a flat area which touches one burner to the next this area is called the spreader bar. These flat bars can get filled with water during the summer if you had a leak on your A/C the water will get in there and turn to rust so you need to take something and clean that area out then reinstall the burners. Let me know is it works thanks.
Alvin, thank you so much for answering.The issue is not the water as the gas valve does not release the gas.
Unless I knock on the valve with my fingers it will release the gas just as the ignitor gets the signal to turn off.
You should be able to get a new valve cheaper by getting the part number off the valve and doing a Google shopping search. Good luck
Alvin Shepherd Thanks a lot!
Hi ALvin. I have measured the voltage on the gas valve and it gives 10.2V until it gets the signal to release the gas. Then the voltage goes to 0 V. Any idea why ? I was expecting to be 24V when the valve was signaled to release the gas.
Bad connection somewhere you're losing your voltage so when the gas valve actually has a draw for current it drops to nothing. Try jumping out the thermostat at R & W if that doesn't work jump out the circuit board on the furnace at R and W. Also try tightening up all your low voltage wiring connections.
Alvin, I have an AMANA 90 Air Command. A couple of years ago I had a lot of problems with condensation in the induction blower. I would take it off, dump the water and then reinstall. It would work for a while but continued to be a problem. The furnace had worked for years so I knew it was not an installation issue. Seemed that there were many post concerning it but none helped. It turned out that the elbow connecting the blower to the vent was the problem. I could not see it from the blower side but when I disconnected the elbow from the vent, there were remnants of a "dirt dauber" nest that had blocked the drain coming from the vent side. Just thought that I would share in case someone else is struggling with that particular issue.
+Michael Braden Thanks and its a good idea to cover you vent pipe outside with a piece of hardware cloth that has 1/4 inch mess screen to prevent that as well other rodents and such. Cheers...
pulled both doors off furnace to vaccum clean burner area when I replaced the filter! ..replaced doors wrong way top and bottom...noticed when my house went cold...put doors back on right way and still no heat...so with your suggestion i reset the roll out switch and BINGO..thanks man!
Thanks for sharing this video Mr Shepherd, it helped me to reset my sensor...
I just wanna say thank you very much..very helpful and educational
Great guide. Thanks for taking the time.
I have installed a couple of the ventless fireplace logs, and noticed the house had a fume gassy smell. I was thinking of putting one in my home and did a search on consumer reports to see which ones they recommended. I was suprised to find that consumer reports did not recommend any of the ventless heaters because after 5 hours of operation there were none that were still within acceptable standards of carbon monoxide. So no I'm afraid, it is too good to be true. Unless you like fumes.
Thanks for the list of comments. I've reviewed the issues for similar problems and just need a little assurance that I'm headed in the right direction. I have a 12 year old two stage Airquest furnace. I'm installing a new wifi thermostat and and have run into an issue where the blower runs constantly, even when in the fan AUTO mode on the thermostat . After troubleshooting with the thermostat company HELP support, (thermostat tests OK) we discovered that at the furnace blower control panel, with all thermostat wires removed, I have 24 volts from the R to W2, R to W1, R to Y, but only 17 volts from R to G terminal. I went out on a limb and ran a jumper from Y to G to provide 24V at G and retested. The system and blower seemed to be normal in both heat and AC modes. Upon visual examination of the circuit board there are two brown spots around components in the lower part of the board that look like they lead to the G terminal. I assume that the board needs to be replaced. Before I do that, is there any diagnostic to perform on the system? Really appreciate your help with this.
Stranger, Hmm did you mean C to R etc. you got 24 volts? Not saying that you can not get voltage from R to W but those voltages are coming from a coil which is not energized. What I am trying to say is C = common R = Power will give you 24 volts however R and W have the same potential the only way you are going to see power there is when the common is coming through the winding from the other side of a coil or motor. I am going to put up a video to try to explain what I am saying. Stay tuned and I will try to have it up within a few hours. For now simply disconnect all the low voltage wires at the furnace if the blower continues to run then the problem is internal. Be sure and check the High Limit switch to see if it is open that would cause the main blower motor to run. It could be the circuit board but if everything was fine until you installed the thermostat I would start there.
I really enjoy your videos thanks and God bless you my friend.
If I suspect flame sensing, I use 105 c rated wire and attach it to the burner, this acts like a flame sensor too, and I terminate the wire where the flame sensor goes or ground or burner ground all on the module of course. this assures you have 2 nice paths home to prove the flame DC signals able to get home.
+Kd Grayson Good idea two heads are really better than one
wow I had no idea there was a circuit board in heaters. They are very complex. I was easily able to diagnose and fix my air conditioning problem last summer by noticeing the shreaded and pathetic blower fan belt laying on the bottom of the box. Was very hard to get the supply place to sell on to a home owner though. What do you think of the wall units you can buy to use in a power outage or small home? 99% efficient they say
my problem was the flames on my blower we're not turning on. problem solve ! at 8:25 minute of the video the toll over switch did it. thank you.
Alvin thanks for the informative video.
I Have a Ducane M/N 80G1UH070AP12-02. Sometimes works just fine but sometimes the ignitor will light but gas will not come. After three times the furnance will stop and it will take 3 hours to start again. I cleaned up the flame sensor. It seem like a made a difference in that day but it came back to its issues again. The code 7 flashes says Lockout due to no ignition.
Any idea what might be?
Thanks for sharing this video. Just awesome that people are still willing to help.
My issue is....
Therm calls - check
Inducer comes on - check
Igniter comes on and bright red - check
But then.......
Whole unit goes off. Board went black.
The light on the board went off so I can't even check the code.
I turn the emergency switch off for a sec.pond then back on. Light on board comes back on but no code.
So it seems everything works up to gas igniting.
I'm stumped.
Wondering if you could help with any ideas.
First try disconnecting the power wire going to the gas valve. Then retry the start sequence. It maybe that the coil in the gas valve has shorted out causing an overload in the circuit board. Also you can take an ohm meter and ohm out the coil in the gas valve. I believe the resistance should be around 75 ohms. But if what I'm saying is true then your resistance would be near 0 to 10. My guess is that you have a bad gas valve.
Have a Armstrong furnace shooting a 4 flash code, meaning a roll out or high temp limit open.
I metered the limit switches, all good. Aux limit good. Pressure switch good. I jumpered the limit switch out wire, and the return line back, on the 6 pin molex connector on board. I turned on power, and furnace went through the correct start up sequence. Checked with meter between the 2 molex connections and had continuity with and without the jumper. Removed the jumper, applied power... board showing 4 flash again with inducer and fan motor running as before. I think the board is bad, as all limits are passing fine. What do you think Alvin? Furnace is around 9 years old.
Just make sure you are not missing any of the roll out switches. Some models will even have a high limit located on the blower assembly in the event the blower motor is malfunctioning. The high limit and roll out switches are sometimes within a seperate circuit as well so ensure that you have power coming back to the board on both your roll outs and limit if so then it is a bad board. Pull the board and carefully check the back for any signs of where it let the smoke out also play close attention to a weak solder joint which will show as a ring around a soldered pin as it protrudes through the back of the board. These can easily be repaired if you have a soldering iron, but anything more than this you're probably looking at a new board. Take the part number off the board itself for a Google search and Good Luck...
Thanks. I regularly repair all appliances, and furnaces, and familiar with most. It wound up being a bad board. I replaced some components, and have a back up now.
Great educational video Alvin. Thank you. Any idea why I don't see gas flames above the hot water heater and inside the gas heater furnace? These two units are collected in the basement. Gas stove in the kitchen works fine. both units were working fine but all of sudden seems like gas supply to these units is cut off. Thank you.
+jyprkh Since both units are effected then it could be that the gas was turned off in the neighborhood which caused the pilots to go out on both. This is where I would start the water heater will usually have instructions for lighting the pilot. However if what I'm saying is true then you could have air in the lines as well so getting the air out of a line by purging it out through a pilot orifice can take forever. You might can report a problem to your gas company and they will come out for free to light your pilot. But that probably depends on your supplier. I don't feel comfortable telling a homeowner how to purge the air out of gas lines as it does have some danger.
+Alvin Shepherd As far as your furnace goes it could be the same thing after 3 or 4 tries with no ignition your furnace will lock out. You may try resetting the furnace a few times to see if gas will start to flow and ignite. There should be a power switch located near your furnace unless your panel box is within sight These switches will look like a light switch. Which I have seen turned off inadvertently as well in the past. Anyway If your furnace has a lockout code on the circuit board then this would be my best guess again is air in the line. Since it affecting both heaters.
+Alvin Shepherd Lastly there can also be pressure problems that a stove may not be effected by your home will have a pressure regulator at the meter but you will need special tools to determine this so I would call the gas company if you find out that you are indeed getting gas to the water heater but that it is not staying lit.
First off all, a MILLION THANKS for your time and sharing your insight into the issue, tips, suggestions, and cautions. You really have thought through my issue and I appreciate it a lot. I have noticed that the gas comp has been doing work in the last few days about 1/2 mile down the street. Unfortunately they are closed today but will call them first thing in the morning.
+Alvin Shepherd You are correct, there is a power switch but that wasn't turned off inadvertently. Yes, I saw one LED flash (quick flash) when I looked through the little eye piece and I am working on finding out the code/error etc. I am very hopeful that it is just a matter of releasing the air in the line with the help of the gas comp.
Thanx for your response, much appreciated.
Loved your methodical approach to inducing the furnace operation. I just installed a new goodman 95% efficient and I can't get the inducer motor to stay on for more than 5 seconds. I converted it to propane and have the valve screws 2-1/2 times around open. The condensate line is connected and primed with water.. any thoughts of why an new unit won't start?
If the Inducer motor is shutting down. In all likelyhood the pressure switch is not proving and it is locking itself out. In a 90% and higher furnace there are lots of things to cause this. They are very sensitive to unburned gas for one and since you have converted it I would start there. You need to set the gas pressure with a manometer. There is a port located on the gas valve to do this you should be able to find a good video on RUclips describing this procedure. Once you have done that make sure you are not trapping condensation check the hoses especially the pressure switch hose for moisture but also pull the drain hose off the inducer to see if it is filling up with water. If it is then double check to make sure all those hoses have been installed in the correct position. The hose locations change according to how the furnace is installed so go through the installation instructions carefully to ensure they are in the right place for your install.Hope this helps but unless you did this job yourself I'd tell the installer to get his ass back out there :-)
Thanks Alvin. Turns out it was the new thermostat they had installed.
You explain very well, and I learn a lot from your video. However, it cuts off near the end. Do you have another video follow up this one? I would like to watch the next one. Thank you very much!
Van, I have not made another Heating video. I've wanted to do another one which will discuss other problems and will try to get one out before the new year. Please check back after Christmas as this has been one of my more popular videos. Thanks
Hey thank you so much for this extremely thorough and informative video. You took your time out to do this and it has helped me 1000 fold. Thank you sir.
Thank you, Alvin. I will check code and let you know.
Hey, great video and very informative! I have a weathermaker 8000 that occasionally cuts out. It usually works fine, but sometimes it will light, work for 20 seconds or so, and then the flames go out. It usually tries again immediately to light and does the same thing. It'll do that a few times before quitting totally. Usually turning off the thermostat, power cycling the furnace, and then turning the thermostat back on makes it work. Any ideas? I'm wondering if it is a bad board but I'm not sure
You should clean the flame sensor regardless, if that doesn't help try to get a diagnostics code to narrow the problem down. It could possibly be a fault in the circuit board some of the large standoff resistors get very hot as a result they can cause the solder joint to become weak. If you can't find the problem within the diagnostic codes with nothing stored then remove the circuit board carefully and do a detailed inspection of all the solder joints on the back of the board paying particular attention to anything that looks like it has a ring around the post. Sometimes relays can do this as well. You may try resoldering the board if you're willing to do that give it a shot, Good luck...
Thanks for the ideas. I cleaned the sensor last night and it has been running alright since then. Hopefully that is it because I'm not sure I trust myself to solder the board!
GOOD ON YOU BROTHER. THIS HELPED ME GET IT WORKING. THANK YOU
Thank you for the clear orientation.
thank you so much for your explanation, i am taking hvac classes and this helped me a lot.
Yes it comes from the ac compartment on top of unit,it had some brown sediments in bottom that I vacuum out then flush the line to to outside.
If this is a 90% furnace the condensate pump which pumps the water out of the unit should have two small wires with wire nuts attached to a small thermostat like wires. Try connecting the two wires that run into the furnace together and see if that works. The furnace does not have an error code and those two wires are a safety shut off. They are low voltage so they are not dangerous but dont strip the wires in your mouth.
Also if that is your problem then the outside condensate drain hose is probably frozen? How Cold is it there? Anyway that maybe your problem, it could be frozen is so you need to route that hose so that all the water can drain out after it exits your house walls.
If you are considering a wall unit which has a vent, they're great and need no power to operate. Any of the powerless heaters with a vent are good, but personally I do not care for the odor of the ventless units.
The problem of blow cold air is happened only after several days it is functioning properly. My furnace is Trane XB80 without a little window, so I could not see what code. After removing panels, there is a safety switch shuts off power, put them back, the burner running and it works good. When it blows cool air, the burner is not running at all. Thank you.
Tuyet Le I'm afraid you may need a service tech who can help you some problems like this just cant be diagnosed without an on site tech.
Thank you very much.
Really like your video it helped a lot, Should the inducer fan run the whole time the furnace is running? thanks for your help
Yes, unless you'd like to see the furnace catch on fire :-)
As long as the fire heats the house LOL
again thanks for your help I got my heater going
Yeah, I'm afraid so. I purchased a 10,000 BTU model / Cozy World off Amazon which used Natural Gas and had to return it. I know I wouldn't buy another one. I'd get something which has a vent flue for the exhaust gases...and that required no power. Floor Models like the old one I had when I was a kid can do a small house, but it would depend on your climate and sq. footage.Thanks for Posting
great site! I have a15yr. arco air 90+works fine however it makes a motor sound. runs for 15 seconds stops and repetesthe same. disconnected exhaust fan and problemstill continues. please help.thanks
I have a Ruud Silhouette II. Most of the times it will not start heating until we tap the vacuum switch. After tapping the vacuum switch then it kicks on the inducer. What fix do you recommend? It is really bad cause it will turn off in the middle of the night and not turn back on. Thankfully i live in Texas where it does not get really cold at night, but still i would like to try a DIY fix if I can.
Great video. I have a trane XB80. The start-up sequence goes all the up to the point of lighting the main burners, but they don't light and I don't smell any gas. I do get 27V coming from the curcuit board across the valve, but no main burner fire. I've done all the other basic stuff, but no luck. First time to fire the furnace this year. San Antonio, Texas. Any help would be appreciated.
Well, as a technician I would loosen the union and listen for gas flow and the rotten egg odor then tighten it back up. If you have good voltage at the valve when it is calling for gas then the problem is in the valve check this video on testing a valve How to test the gas valve on a gas furnace with an ohmmeter now there is such a thing as ghost voltage. If it appears to have the correct voltage but when the load is actually applied such as the valve the voltage goes away. This is caused by a weak circuit most suspect would be the thernostat for this. Simply jump R to W to go around the thermostat if you are looking for ghost voltage until you find the culprit.
I also found once where bees had gotten into the burner manifold orifices and clogged up the gas flow. If your furnace is in the attic and you have gas at the union you might try inspecting the manifold orifices just to make sure.
Generally, if you have gas flowing through to your valve and it's getting 25-29v but still not opening it's the gas valve. Makes sure it's getting voltage everytime.
So many of these go without telling what actually fixed it in the end, so here goes. I ended up making two jumpers that I could use to tap into the 24V supply coming from the units 120V to 24V transformer. I applied that to the gas valve's solenoid. At first no gas flow, but after a little persuading (ie lite tapping) I heard the gas flowing. I removed my jumpers and let the unit go through its start-up cycle and hallelujah it fired right up! So it appears it was a sticking gas valve. The unit is 10 years old, and it looks like the folks that installed the unit did not put in the normal "low point" in the gas plumbing to catch debris and maybe this is causing the valve to stick following a long period of inactivity. To be safe and prepared for trouble free operation next season, I ordered an upgraded valve and will correct the plumbing install when the weather warms which doesn't take too long here in San Antonio typically.
The pressure switch in my furnace had failed and needed to be replaced, this had caused the issue of the burners lighting up and shutting off after a few seconds. Once this was replaced by a professional, it is working fine now.
I suppose a bad gas valve can cause that problem too.
I recommend this one Williams 30,000 Btu/hr Direct-Vent Furnace Natural Gas with Wall or Cabinet-Mounted sold at Home Depot for about 600.00 It cost more but if you're using it to heat the house it is going to be better.
Alvin awesome video. super informative. I have an issue with my unit. the igniter goes on and off for times and no gas goes thru the unit. I then turn the entire unit off and on again two times and after the second time the unit will ignite and the gas will run through it and heat my home until desired temperature is reached. when my home drops in temperature again and the unit needs to run it have to turn the unit on and off again by hand. I hope I gave you enough info to have an idea on what may be my issue but if not I can provide more. I have a arcoaire brand unit. I sometimes get a 6+1 led status code. which is tied to ignition lockout.
+dannyny Now there are a few things it could be. It could be that the gas valve is not opening properly. Also it could be a dirty flame sensor which doesn't always allow the unit to come on. I would go ahead and clean the flame sensor just take a pencil eraser and clean off any oxidation that might be on it so you can rule that out. If you're still having problems try to watch it to see what its doing. Does it really try to ignite the flame but just no gas if so you need to be looking at the voltage at the gas valve when it is attempting the gas. Are you getting the correct voltage 24vlts AC at the valve. If not then you should disconnect one of the leads probably marked MV on the valve and then check it again with the lead off ( The voltage is applied to the valve after the igniter has been glowing for about 30 secs) if you had low voltage before do you have low voltage now? If not then its the gas valve it has a bad coil with low resistance. Change the valve. If you have low voltage with the wire off but good voltage at C and W on the main circuit board then the problem is in the circuit board. As long as all your wire connections are good. You should also check the High Limit voltage as well and any roll out switches to ensure they are all sending good voltage through them as well. Hope this helps...
+Alvin Shepherd thank you for the reply. I understand the first half of your reply but I'm not too handy to deal with electrical. I do know the igniter strip lights up and waits for the gas to shoot out but it does not then the igniter goes off and tries again. after 4 tried the system shuts itself down. I read thru the troubleshooting label and it mentions one of the wires has to be grounded to the sheet metal of the body of the unit itself. I took the wire off the fuel rail? and screwed it into the sheet metal and it seems to help as it comes on after its 3 attempt now instead of restarting the unit and trying 2 to 3 times. if you suggest the gas fuel rail injectors are dirty I can try to take it apart and clean them? my father installed this unit one day with his friend it was kinda like a diy install. he also cleaned the flame sensor with a metal pad. looks pretty clean. any feedback and help is greatly appreciated!
+dannyny Are you saying that you took the wire off the flame sensor and screwed it to the sheet metal. If so this has to be removed asap. What you are doing is wiring around a safety which prevents the furnace from operating unsafely. The flame sensor detects that the burners are all lit and that the gas is burning in the right place. Imagine what would happen if the flame was lit but was just burning inside the furnace compartment instead of going into the heat exchanger. Danny I enjoy helping people but there comes a time when you are better off leaving this to a professional. If you are not comfortable with electricity or do not own a volt meter there is simply no way you are going to be able to diagnose the problem with your furnace.
+Alvin Shepherd i did not place the wire from the igniter that has two white wires coming from it. the wire i placed on the sheet metal is from the control gas valve it is the green and yellow wire. on the diagnosis troubleshoot sheet it stated it MUST be grounded to the sheet metal. I did call professional help but he came saw the machine was new and said looks fine and left. it has been running for 3 years but last season it started failing. thank you again for the help. it is super informative as I said before.
Ok, It is difficult to understand what you are talking about when you say you took a wire off and connected it to the sheet metal. If you are talking about a green and yellow wire then that will just be a ground wire. No problem. But it still doesn't negate the fact that in order to test to find out which one of the components are failing you are going to need to have a volt meter. You are going to have to know how much voltage the gas valve is getting. It should be 24vlts AC but if it is not at least like 22 or so then you are going to need to determine where you are losing the voltage. This cannot be done without a volt meter.
We just bought a home in Indiana a few weeks ago. It has a TAPPAN Model # L1RC 080D-16B furnace 2005 or 2006.
Last week the furnace would turn on, but stopped igniting and blowing hot air. The flashing light indicator showed it as a pressure switch open w/ inducer running error.
Each time my husband would jiggle the cable it would work again. So he replaced the insulated terminal and we didn't have any more problems for about a week. Then of course at 3 am today (Christmas morning) is happened again. We unfortunately don't have the connections we had back in Michigan and would be happy to get any suggestions.
One thing I'd check on a cold holiday night is to see if there could possibly be water in the vacuum hose going to the pressure switch. Now I do not recommend sucking or blowing on the pressure switch. They are made for very low pressures and it could damage it if it is not already bad. If you have a volt meter you can check to see if you are getting voltage across the pressure switch. with one lead to ground you should have 24 vlts. on both sides if the switch is closing. About the water issue if you do find water in the tubing get it out and remove the pressure switch and lightly tap on it to see if you can remove any water from it too. This may not be a lasting repair but at least it could get you to when the supply houses open...Good Luck
Part 2 Also If the vacuum switch is getting water 1)There could be an issue with the placement of the switch or
need a modification as some switches have a vent hole which continually pulls in a slight amount of air to prevent a moisture problem.If you find water in the hose or switch I will go into more detail of how to repair this issue.
Would a bad condensate pump cause the same problem? We noticed there's water in this tube going from the pump and furnace to the sewer pipe. It doesn't sound like this little guy is running. Looks like it's a "Little Giant" pump.
We didn't noticed any water in the lines coming from the pressure switch. My husband said he'd check the voltage when he gets home from work. I can't tell you how absolutely gratefully and pleasantly surprised we were to see you respond to our current woes. Thank you from Indiana!
Dawn Vanneste It seems so sporadic. When the furnace wouldn't blow and we would jiggle to connector going to the pressure switch, it would start. Now that doesn't seem to be working anymore. This last time I couldn't get it to start until I tapped the pressure switch itself gently. Any tips, ideas, and suggestions are so greatly appreciated.
Excellent video and tutorial! I was able to diagnose and resolve my issue. Dirty flame igniter. THANKS very much!
I had to pay someone $250 to fix that. That's why I am here learning how to do it myself.
Thank you for the great video. I am getting the 3 fast 3 slow blink code on my Carrier furnace. Flame igniter is new. Flame rod looks pretty clean. Inducer turns on. The furnace will run for approximately 2-4 minutes and will then stop the gas/heat while the blower continues to run a few minutes while emitting the 3 fast 3 slow code. It then recycles. Air filter was clean but still swapped it out with a cheap commercial style filter with barely any filter ability and the furnace will run. According to the code it can be many things. Seems to be an air flow issue of some sort. The furnace is 16 years old now. Do you think it could be the blower motor not up to "speed" anymore? Any tips or advice would be greatly appreciated. Thanks.
Check your High Limit Switch and also the Roll Out Switches to ensure they are all in the closed position. Using a volt meter with one lead connected to ground you should get 24 vlts. A/C on each side of the switches if it is closed and only on one side if it is open. Sometimes these switches are ran in series so some may have no voltage also. Hope that Helps....
Hey Alvin. Thanks for the video. I was hoping you could give me some advice. We have a York furnace and we lose the flame if it has to run too long. Most of the time you wouldn't even notice. But when it gets too cold outside (and therefore inside) the furnace will lose it's flame but the fan keeps going. Once that happens of course we get no more heat just a blowing fan and a very cold house in the morning. As long as the temperature can get up to where the thermostat is set within a short period everything works. If I set the thermostat 2 degrees higher than the room temp it loses it's flame before it can get there I remember having this problem in the past and I believe they replaced the control circuit card. Does that sound like the likely culprit to you?
It sounds like your system is either locking out after a few tried attempts to re-fire or you have a high limit that is over heating. If it is the high limit then it will shut the gas valve off and keep the blower fan running. This can be caused by low air flow. That can be from allot of factors like a clogged air filter, dirty blower wheel, covered up return registers etc. You can tell if the unit is starving for air by running the unit with the blower door off and then use it to cover the opening if the door is slamming up against the furnace then the problem is before the blower. If not the problem maybe in the blower wheel or after it. You may want to check the evaporator coil to see if the coils are covered with dirt as well. You could also have a bad circuit board if you cant find any problems with air flow. Remove the board and examine it very carefully to see if you can detect any gaps in the solder connections. These can be difficult to see but ussally appear as a ring around the pins. Hope this helps...
Good explanation very clear and easy to understand , thanks
I had a 10 yr old York furnace up in the ceiling, It stop working and I just replace the surface ignitor with a new I put it on and I saw its firing flames but it didn't blow any air at all. I did check the flashing red which is 4 blinks which the diagnostics says High aux. or spill limit switch open. Could you explain more on this, I really appreciate your output on this. Thanks
They are refering to the parts I call the High Limit and the flame roll out switch in the video. They are both wired in series the roll out has a reset button. You can check to see if one of them is open by using a volt meter and placing one lead on the unpainted metal in the burner section then putting the other lead on one side of the switch then the other. Both sides should show power 24 vlts. if the switch is closed. If only one side shows power then the switch is open. The High Limit is auto reset so if it is open and the furnace is not hot then it is bad.
Alvin Shepherd Thanks Alvin for the prompt reply. I'll give a try on your advise, also I forget to mention that before it stop working i smell like a burned plastic kind of thing on the duct that when found out it stop working, Im afraid it might be the motor of the blower or something else.
let me add. it stops for 10 seconds then continues to repete the same noice.thanks again!
The system operates off the principle of "flame rectification" that is a flames ability to "rectify" an AC signal to a DC signal, thus proving a flame exists, otherwise no DC signal will be sensed .
A flame sensor is a metal rod that receives a DC signal through the flame, sent via the igniter.
The flame is an electrical conductor, but more relevant it "rectifies" an AC signal to a DC signal, the "flame sensor" is a rod that "senses"a DC signal.
Many units have no flame sensor however they operate alike.
Their DC signal is "sensed" via the burner ground which if you notice terminates on the ignition module on ground or burner ground.
The DC signal is mere millivolts as the flame is a poor conductor, it does not take much to interrupt the DC signal returning"proving" the DC signal exists thus proving the flame exits.
0000 steel wool is best to clean a flame rod/ flame sensor.
Most units today have a diagnostic light that will be steady on or off or flashing in a sequence that indicates a specific fault ,a legend on the blower door tells you the specific error/fault.
If can be a flame sensing issue ,however more commonly found is the induced draft proving switch is the problem, it has a rubber hose that attaches to the induced draft housing that senses the inducers operation .
The pressure switch closes ,telling the ignition module that the induced draft is operating.
The barbed nipple /port on the induced draft housingwhere the pressure switch's hose attaches will clog with carbon about every 2 years on most units, it is tough to clear, I use a paper clip unfolded and make sure the carbon is cleared by hearing the clip touch the induced drafts blower wheel, its easy to trick yourself thinking its cleared.
Hi thank you for willing to help a little bit. The problem I'm havingis, every now and the, while unit is off. The unit sounds like it's cycling on for about a min then off for about a min. It does this for a little while the. Will stop. Nothing g I do seems to fix it or make it stop
It sounds like your furnace blower motor to me. I have seen blower motors cycle On and Off when they are located inside a hot attic when the temperature gets up to around 120 degrees F. You may try adjusting the Fan Limit Switch on your furnace the middle pin controls the Fan On position and by turning this up it will not come on until the unit gets to a higher temp.
maluvillaronga
maluvillaronga
I am having the most frustrating experience trying to set my White Rodgers fan limit control switch. As you may know the limit dial has two pointers, so if you could please PLEASE tell me where to go from there, I'd really appreciate it.
+Ta'Shawnda Price Ok if you look on the dial you will see two which are adjustable and one which is fixed. The fixed pointer is the limit this is the safety which will kill power to the gas valve in the event of an overheating condition. The next one closest to the fixed pointer is the Fan On switch that turns the fan on. The last one is the fan off. Now here's the kicker, if you are having a problem where you cannot get the fan to stay on they have a fan limit model that has what they call a heater. There are two more wires coming off the back and those tie into the gas valve (Low Voltage only circuit) Also make sure you dont get any of these wires confused as you can do serious damage by connecting a low voltage circuit on the limit into the high voltage fan circuit. Anyway the fan heater is designed to prevent the fan from short cycling so that anytime the heat circuit is energized the fan will stay on. Yeah I know this bites, Good luck...
+Ta'Shawnda Price Now normally the Fan off position should be set around 110F unless your furnace is located in the attic ( in that case you can actually have the fan come on in the summer you may want it higher) But generally around 110F then the Fan On should be set up around 140F or even 160F but not any higher. If you are having a problem with the fan going on and off even with the fan limit set at 160 then you're going to need a new one and you may want to go ahead and get the one with the heater cause otherwise you're taking a chance that it will do the same thing. Good Luck
My Bryant 90 plus is 20 years old stoped heating. I find that by flipping the power switch (The one on the side of the heater that looks like a light switch) off then back on, will usually get it running again. If not. Then I'll bang on the side by the switch a few time and It'll be up and running again for a day or two. What needs to be replaced. The power switch?
Maybe, what you really need is a volt meter. They are cheap and are great tools if nothing more than sorting out good batteries from bad ones. The problem is that by shutting off the power to the furnace that will reset any lock out that the furnace was in. It still wouldn't hurt to rule out the power switch just the basic light switch only cost about $1 dollar. But inside the furnace on the Circuit board there is an Led light when your furnace loses power that light will go out. If you find that the light is out until you knock on the switch then I would say yes you have a bad switch but if that light inside the furnace is blinking then you need to watch the light to see if it has short and long flashes there will be a pause and then it will repeat also there will be a diagnostic code usually on the blower compartment door on your furnace that will help to diagnose the fault. Hope that helps...
good video, a lot of useful information
I have a New Yorker oil furnace. It runs fine most of the time. Every so often the fan stops. If I go down and tap the fan box, it kicks back on. Needless to say if we are not around when this stops running it tends to get quite cold. Any ideas?
I don't know that much about oil furnaces as they are rarely used in the South. However it sounds like you may have a sticky Fan Limit switch. This switch has a bi-metal spring which extends inside the heat exchanger and as the temperature rises the spring turns a dial with 3 tabs two of which can be adjusted. Sometimes adjusting the Fan On and Fan Off tabs can correct the problem you're speaking of however most of the time you should replace this part. If you will watch this dial as the heat exchanger heats up it should slowly and consistently turn if it sticks, then when it finally lets go the High Limit part of this dial (The 3rd tab) will cause the fuel to stop. So that's where I'd start.
Bumping this control will free it up, so when you say tapping on the fan box corrects it is why I feel that it is the Fan Limit.
These are not log style but are called procomm 3000, still a bad idea?
I have a goodman furnace,it lights sometimes then I just here a click and blower but won't light,I changed the flame sensor and cleaned out trap from induces still same.
Without removing the furnace door look through the little window on the blower door there should be a error code led light. Ussaully on the blower door there will be a diagnostic code what error code are they telling you?
You mention a clean out trap is this a 90% plus furnace? With PVC white plastic vent pipes?
My furnace ignited and burn 3 seconds and turn off it repeats the cycle 3 time then fan turn on nonstop with error 2 red flashes. Have Changed flame sensor and pressure switch but problem stills the same. What’s next troubleshooting?
The vacuum pressure switch needs to have a good hose with no holes I have seen rodents chew on the hose making a hole in it. Also the port that the hose connects to on the induced draft motor needs to be clear you can take a Jim Clip and push the end down inside the port to make sure it is clear of debris. Last you need to make sure that the main circuit board is grounded if not it can't get the proper signal from the flame sensor. Hope that helps.
The heat unit from my business is a carrier one and the blower works and it sparks to try to turn on but looks like the flames won't come on do you know how to looking for that part or how to change looks like the gas is no coming true
Some older Carrier units have what I call a 3 wire pilot. The spark ignition device ignites a pilot and has a yellow, green, and white wires coming out of the bottom of it. When the unit calls for heat this device ignites a pilot then after a few moments it allows the main gas valve to receive power and gas to flow. Is this the type system you have. If so the problem is usually within the device itself, usually the problem comes in where the device cannot prove the pilot is lit.
We have been setting our thermostat at 71 and the heater wont kick on unless I turn the thermostat off and then on. It will kick the furnace on but won't stay on.
The furnace is locking out. After 3 or 4 attempts to ignite the gas the furnace will lock out. When you turn the thermostat down on some units the furnace will reattempt to work. You need to try looking in the window on the blower door to determine the diagnostic code this is in the video Thanks
It does not have a window. The unit is a kelvinator. Can I tell a different way.
Does your furnace have a circuit board or does it have a pilot to light the burner?
I opened it up. Dusted it out. The led lights establish there are no problems. And the thermostat is at 70 and it reads 70. I don't know why it locked out last night. As I said this morning, I had it set at 71 and woke up to lower 60's until I turned it off and then back on. And thank you for your help.
Does the furnace information decals show that the circuit board has any diagnostic codes indications? Not all do but if it does it should list the error codes probably on the furnace door. If you do have error codes with no window. Temporarily tape the door switch closed so you can get the door off without it losing its history lockout condition and when it fails again check to see what the error code is.
HI i got a question for whoever knows the correct answer..... I recently came across a new pool heater in Canada and there is no shut off going into the ground after the meter and there is also no shutoff behind the shed where the GASTITE goes in but there is one shutoff connected to the valve train before the gas valve. Does anyone know if you need those extra shutoffs and if so what code is it in the CSA B149.10 code book thanks
I have a four year old 90% efficient York heater in my attic. The heat goes on at the right time but then shuts off while the fan keeps running for as long as it takes me to get up and turn the thermostat down (sometimes half an hour). I just had a service man here who couldn't fix it. I'd like to get it fixed while it is still under warranty. This problem has happened since it was new. Any suggestions.
90% Furnaces are also called condensing furnaces. They make water from the humidity in the indoor air. That water can collect in the vent flue if the venting is not ran properly. The vent flue can either be ran to drain outside or back into the furnace but it cannot have sags where it will collect water as it goes outside the house. Also these furnaces can be sensitive to the type of intake air you have. If your unit has an exhaust and outside air intake check to see how closely they were installed at least 12 inches and the intake flue should never be installed above the exhaust flue as it will pull the steam condensation gases of the exhaust. These gases will cause the furnace to malfunction. Hope that helps. Another thing they make water and that water drains sometimes a condensate pump is used to pump that water out. If the condensate drain is holding water outside in the winter it can freeze. Here you will ussually notice that the condensate pump is full of water and running non-stop. If this happen you can ussaully cut the discharge tubing near the house or reroute that tubing so that it will not hold water. Check those out and let me know....Good Luck
thanks for your response. there is a 3/4 inch pvc pipe that gravity feeds the condensate to the outside. when the heater is on, water drips out of it. I'll see if I can get more slope on it. you might like my video from Nat Geo ' Chile, great prison escape" .www.amazon.com/dp/B00AUN9RHY thanks again. Tom
The vent flue is a 2 inch PVC pipe which vents the exhaust gases from your furnace to the outside of the house. There is high moisture in these gases which create condensation. If this piping is ran in such a way (dips and slopes) it can hold moisture these furnaces are very sensitive to even a small amount of pooling water. On your condensate drain I was referring to the discharge tubing which is a 3/8" Vinyl tube that comes off your condensate pump and runs outside those can freeze up outside in cold weather so you might check that too.
another tech finally diagnosed the problem. there was too much gas pressure going into the manifold. it works good now. thanks
My furnace works but is acting up.. There's a delay after you here the click from the thermostat. The furnace starts humming and kinda buzzing before it actually ignites.. Any thoughts?
My guess would be a buzzing relay. But you might try carefully putting your hand on some of the components inside the furnace while this is happening. Being careful not to touch any wire connections and get shocked. The part which is buzzing should easily be identified that way. Sometimes low voltage can also cause this so check your voltage without a call for heat and then with it calling. If the voltage is dropping below 24vlts then you may have a wire shorting out where the insulation has become damaged or a coil going bad. You can isolate electrical problems like this by jumping out the connections at the furnace R to W at the furnace calls for heat without the thermostat or thermostat wire involved, Same thing at the Thermostat takes out the thermostat but not the thermostat wire etc, Hope this helps...
I am having trouble with my propane furnace it is a American Standard new in 2014. It has just barely started acting up. Right as the blower kicks on it has a sputtering/ rattling sound for about 2 seconds once the blower is on there is no noise. The rattle/sputter is not very loud but it is there. It heats good and everything seems to be working fine. For the past three years there has been no noise at all and this is something new. I want to know if this is something like a cracked heat exchanger and should I worry about leaking harmful fumes any help would be greatly appreciated.
Should my ingniter fire stay lit at all times near the burners??..and my pilot light flame is bigger than it was before I had some repairs is that normal???
Lonnie about 1990 furnaces replaced standing pilots with ignitors. So if your funace is made after 1990 I doubt it has a pilot unless it has an intermittently lit pilot which was around for about another 10 years. Now you are saying that the pilot flame is staying lit all the time and that it is bigger than before. It sounds like you have an older furnace and yes these stay lit so that they can light the main burner when your thermostat calls for heat. If the flame is bigger than it use to be it maybe that the repairman cleaned the pilot assembly or he could have even used something to enlarge the pilot orifice. I dont recommend doing that because the pilot orifice hole is so tiny that even a sewing needle hole would be much too large. So he may have done that. If the pilot flame is more like a torch now than a little pilot flame then I would say he definitely did do the dirty deed. But if your furnace is that old and the pilot is having problems staying lit then I would be looking more closely into a new furnace. Chances are you have a crack in your heat exchanger which is blowing out your pilot flame so it might be time to get a new furnace. Only an honest on sight technician can determine for sure.
Thank you. Very informative.
If the inducer cycles, ignitor comes on, the gas valve clicks (24v verified), this
says all the pressure switches and sensors are working -correct? The
flame sensor circuit is not even active yet -correct? Bad flame sensors
will only show up after flame should be detected -correct? I have all
of the above, with no flame. Additionally I have a modulating gas valve
(97% furnace) with an additional stepper motor in the valve that is not
turning (took the cover off and made an inspection hole to observe the
stepper shaft end). Bad Valve? Board? or something else? Yes, I paid my bill,
and there is presence of gas at the valve and other appliances work. Thanks.
It's also giving a 7 code lockout -no flame detected.
salvor1, your comment went into spam for some reason so I'm just now seeing your question. All your statements are correct the furnace igniter will not get power until all the roll outs, inducer motor, pressure switch have been proven. And the flame sensor can not be a problem unless you have a flame however that is still what shuts the equipment back down. It sounds like you have a bad gas valve just make sure that you are in fact getting gas and power to the valve. Code requires that every appliance have it's own gas shutoff within reach of the equipment, also there are tap screws mounted onto the control valve for taking pressure test so that's a good place to ensure you are getting gas. Just loosen the tap screw with an allen wrench til you hear or smell gas. There are two tap screws one on the input side of the valve one on the output side. The pressure will be higher on the input side than the output. These taps are there to check gas pressure and to make adjustments using a manometer the output side of the valve should have 3.5 inches of water column. But as long as you are getting gas flow it should lite off. The only case I have ever seen where none of the above helped was when some dirt dabbers wasp made their home in the gas manifold and plugged up the gas orifices.
You are very knowledgeable, but this isn't an effective 'troubleshooting' process. This is what I'd like to see:
1: You turn up the thermostat and nothing happens. Steps. Check A, B, C.
2: Fan starts, but gas doesn't ignite. Steps, A, B, C.
3: Fan starts, ignites, but turns off right away, Steps: A,B,C.
You need to give a process of elimination. I can tell you know a lot of stuff, but you are kind of all over the map. Simplify the process for those of us who don't know. thanks for the information. Appreciated.
I just replaced my gas value and the ignitor is turning red but doesn't want to start still, did start when it wanted by not anymore, do know what the problem could be, could use your help thank you
End up being my control board is not sending the the 24 v to my gas valve, I just ordered it I hope that's the problem, thank for the info tho
+Andrew Ramos check the voltage getting to your ignitor some boards can have problems where they are giving your igniter low voltage. Another thing I have seen also is that the ignitor can be out of position. Lastly you can have an ignitor where the resistance has increased so that it no longer has sufficient current flowing through it. Hence a glow coil should glow very brightly before the gas valve opens it should be a bright orange or yellow not red. Of course a ohmmeter would be a better way to check it along with an internet search for the proper resistance measurement on your part number.
You handled telling us about the guy that didnt take the plastic off the filter well. lmao!
My blower motor is making ticking or clicking noise. Can you give me an idea of what to do about it?
My thinking would be first to check if there might be a piece of paper caught in the blower wheel. Make sure the furnace has no power and turn the blower wheel slowly while checking for debris with a flashlight.
@@AlvinShepherd Good idea if I can see the blower wheel. but I think I would have to remove the large diameter intake tube.
@@crand20033 Okay an Intake tube? There are two motors inside the Furnace the Blower motor is the large motor behind the bottom door. The Induced draft motor is a small motor that exhaust the flue gases from the heat exchanger. When you are speaking of a tube attached you must be referring to the inducer motor. If that motor is clicking or ticking its probably the bearings so I would recommend replacing the inducer assembly. You can do a part search using the model number + inducer assembly. Hope that helps...
@@AlvinShepherd No, when I said tube I mean the large foot and a half diameter duct. that goes to the bottom area where the blower motor is. I would have to remove it to see the blower motor unless I remove the whole blower assembly from the furnace.
Mysterious. the LED light on the control panel shut off and I thought the thing had fried. Took it off and checked the back and it looked like new. I made sure all the connections were tight and decided to reset the roll out switch. So I don't know if it was one of the connections or the reset that did the trick, but when I powered up and pushed the door switch, the LED came on and the furnace is working fine, Can a tripped roll out cause power to the board to be cut off?
No, that would only prevent the Gas Valve from getting power and gas flow. It's possible you had a lock out condition after 3 tries and you simply reset the board. Some of these LED bulbs are in a very bad spot to see them so it's also possible it could have been out of view or behind some wires as well.
If you know for sure the light was out, then it's also possible that when you reinstalled the board you may have tightened up a loose connection. But I've never seen a rollout wired up to kill power to the control board.
I had an HVAC guy install the gas and propane conversion kit to a new Whirlpool furnace for my cabin. I wired it and tried to get it going, but I'm getting a 2 flash error code. What happens is the call for heat is made, the blower starts up, the glow plugs are activated, but the gas valve doesn't open. I hear a clicking sound, but no gas is ignited. The HVAC guy thought it was the main board, which I replaced with a new one, but it didn't make any difference. I'm thinking it might be the gas valve? Any thoughts/ help on what I should do? I'm thinking maybe I can jump the valve with 24 v and see if it opens?
Yeah sounds like a good plan. Sounds like the gas valve to me as well. You should hear the gas flowing after the click. This is a good way to test it but dont rewire it to run even if it works as you have no safety running like that.
If I apply the 24V and the valve doesn't open it's likely the valve. But if it does open, maybe it's a pressure switch?
I assume I can jump pressure switches?
No. The circuit board has to prove that the pressure switch is opening and closing. So they ussually will start the inducer motor then shut it back off momentarily to prove that the switch is closing and opening before attempting to go to the ignitor.
You mention a 2 Flash Error Code. But did not mention what the error was. Look in the error codes what does it say is wrong?
Why does my furnace blow cold air? It works after I turning the electric off to the furnace for a full minutes and then turning it back on.
Your furnace is "Locking Out", this can be caused by several different problems. But there should be an easy way to isolate where the problem is. On the furnace door there is a little window. Next time the furnace acts up look through the window and see what code it is given you. It is sometimes like morse code with long and short blinks with a pause between. Then on the door ussaully there will be a diagnostic error code label. Dont take the door off until you know what the error code is or it will reset itself and you'll have to start over. Once you know what the code is check back with me and I can tell you more about how to diagnose the problem as these codes may only get you into the circuit that the problem is in.
Alvin Shepherd I need to know what the code is indicating not how many short and long blinks the light has. As there are so many circuit board models I could never recall all those.
on my furnace, the pilot light will light up but the flame will not go across the burner. any ideas? thermocouple?
+madonna martin There is a flame spreader bar which is integrated into the burner. It is the flat part of the burner where one burner is in close alignment of the next. What can happen sometimes is that the A/C coil usually located above the furnace will leak and cause water to drip inside the furnace during the summer. This water will cause rust in the burner spreader bar. You will need to remove the burners and take a very small screwdriver and clean out this area especially along the most forward edge of the burner then re-install the burners. This should fix your problem....
It's 50 degrees here so o don't think its frozen,I flushed it all the way out there was no return water coming back.those to wires I'm not aware of this where is it located?
OK if this is a 90% furnace it makes condensation. You mentioned cleaning out some water. So I'm assuming this water runs into a small pump. Many times these pumps go out or clog up. Do you have a condensate pump? Is it running constantly? Is it full of water?
Antonious, Its 4:45 am I'm going back to bed now. Sorry I couldn't help you.
Works fine till it gets to the blower motor, I have to spin the motor by hand then everything works. so is it the motor or in the circuit board?
+Scott Lucken Most Blower Motors found in furnaces are PSC (Permanent Split Capacitor) Motors and will have a Run Capacitor which is connected on two wires (usually brown wires) I would start here. A bad capacitor will most of the time be slightly bulging especially if you take a visual of the two top wire connectors they should be in perfect alignment from a side view and they will be facing away from each other if it is bad. The capacitor should always be replaced anytime a motor is changed and are sized in (Mfd) Microfareds and voltage. Of course you should check the bearings for free movement this can be done just by spinning the blower wheel by hand it should spin easily. However motors are going more and more to sealed bearings so those cannot be lubed. If you have one which can you can inspect the back edge of the motor and there will be a fill port which should have a small cap that can be removed. A zoom spout oil works well to lube the bearings. But there is a port on each end and you cant get to the one near the blower wheel without pulling the motor assembly from the furnace. As far as the circuit board I doubt that is the problem seeing that is you give it a spin it runs OK but you can check the voltage while the motor is under a load to ensure it is getting a good connection if everything else checks out. Hey and be careful...
Thanks for the info. Scott
I hope my fellow HVAC techs are ready for the ultra low nox furnace that will be out in the market in your area soon they are and mandated to require all over California
To be honest I haven't heard anything about it. I'm sort of out of the loop and semi-retired.
Flame sensor is measured by micro amps dc. Not micro volts. There is a big difference.
I stand corrected, I knew that I just said it wrong. By the way I found a flame sensor once that had low amps. Someone had installed a new circuit board and did not connect the ground lead to the board.
Would a dirty filter be a reason why a furnace would not ignite?? The fan is running, just not igniting.
+Lisa Stein No, the only way a dirty filter could have any effect on causing a problem is if the filter was so clogged that the furnace kept over heating over and over until it made the high limit switch go out. At that point the unit will no longer call for heat and most will cause the blower motor to run continuously. You need to watch the unit to see what it is doing. Does the inducer motor start up? If not then this will likely be a problem in either the high limit or roll out switches. If the inducer starts up then you rule out those and go to the vacuum pressure switch or igniter next. But if you watched my video then the Diagnostic code I spoke of will help narrow the problem down for you the most. Good Luck
Its getting below zero and my furnace is being a pain. WHen i first started it a couple weeks ago is coded pressure switch stuck open ( 3 red lights ). does that every year after sitting idle for a few months. But its NOT coding red this time. Green light says normal. Filter is cleaned. I turned breaker off then back on to reset. I turned thermostat to lowest point, then higher. Furnace stays quiet. Not even trying to start up. Its an old mercury thermostat so no battery to change. The wire from thermostat to furnace was replaced by a plumber 2.5 years ago..... thoughts?
Try giving the Induced draft motor a spin and then start it up. It maybe that the inducer motor is stuck from sitting idle over the summer.
@@AlvinShepherd The big black thing> Its been running for 2 weeks, no issue. Then just nothing a day ago although it has the green light which says its ok. How do i make it spin? My thermostat is 20 years old. I'm nervous about trying to replace it on my own, lol
Try jumping the Red to White wires at the thermostat. That should give you a call for heat. If that works something is not working in the thermostat.
My furnace flame lights up and stays on. However it is still blowing cold air out. Thermostat fan is set for Auto, air filter has been changed. Any advice?
Call Fox 5 News. If you have a fire and air blowing across it unless your duct work has come apart and blowing into an unconditioned space then you it will be hot.
Alvin Shepherd I'd look at my duct work, Do you live in a building where there could be fire dampers installed? Fire dampers can prevent air flow if they fail no air will flow. You say you have air flowing are you sure? What you've described is not possible. Blower Wheels can become so covered in dirt that they will no longer move the air check the blower wheel to see if it is full of debris if so the blower assembly will need to be pulled out and cleaned being careful not to get liquids into the motor. Lastly sit with the furnace for about 10 minutes while it is running, if it is over heating and shuting down and then starts back up then you definitely have a blockage causing the air not to flow.
Alvin Shepherd Hi thanks for the response. Typically what will happen is hot air will blow out for about 5 minutes, then it'll become cold. When I go look at the furnace the flames are still blue but the air coming into the house is still cold.
Alvin Shepherd Hi sir, me again. I just wanted to update you on what happened. I located a large vent like area above my garage door in my hallway that was really dusty on the outside. I took a vacuum hose to it and vacuumed all the dust out. Since then my heater appears to be working correctly *knock on wood*
Sometimes these dusty air vents may have a dirty filter located behind them too. Because some of them (The dusty ones are returns) people will sometimes put filters behind them even when they are not intended for one...Good Luck
I have a Coleman Furnace. When it clicks for the hat to come on, the furnace keeps clicking on and off and then after awhile it will finally come on. And when it starts it makes a loud noise and acts like it doesn't want to stay running. What can be the problem? This makes the third year doing this.
+Peggy Garcia Sounds like a dirty flame sensor Peggy do a search on how to clean your furnace flame sensor I recommend using a pencil eraser to clean it, but don't use sand paper. Sand paper will take off the rust protection and will cause it to fail more often.
Peggy Garcia
Peggy Garcia
Alvin Shepherd
My furnace has a Honeywell sv9501 smartvalve and when I went to start my furnace for the first time this year nothing happens when i do the recommended 5 minute "reset" indicated on the sticker. Nothing happens with the thermostat, pilot, or any other parts or motor. Its like nothing is getting power at all. Im going to kick myself for not paying close attention, because last time this happened the repair guy came out and messed around with it for less than 5 minutes and everything was ok......any advice?
First, are you getting an LED error code? If you look through the window in the blower door there should be an LED light blinking. If so check to see what code it is giving you. Second if you have no LED on the main circuit board the circuit board has a fuse check that. Next check your panel box for any tripped breakers. After that you will need a volt meter to make sure you have power coming into the furnace from the house. You should also check to see if you have low voltage on the circuit board R = Power C= Common you are looking for 24 vlt AC. Next take a jumper wire and go from R to W (Heat) with the blower door switch closed this should call for heat if it does the problem is in your thermostat or the t-stat wiring. Let me know...
Alvin, ok here's what I came up with. It keeps blowing fuses as soon as the furnace kicks on.