Great videos as always. Well explained and I love the way you laid out all your components. This helps all of us a lot. Keep up the good work as always!
Craig you are going to need a furnace book to complete the set of books you already have and your videos then act as a great complement. Always well explained and laid out.
I wish training videos like this were available when I was a kid since my dad forced me to learn at the age of 12 and we had to order books through snail mail or request our local library to order them which would take 5 to 8 weeks for delivery. Back before the Internet was invented..
@@THExBIGxBADxWOLF93 it good for the simple ones who get over whelmed seen too many things that are spread out . Some students learn better when everything is like on one page in front of them . Have to teach different types of students learning abilities differently. Some students can learn just by reading words without ever seen an actual furnace . Other students literally have to put their hands on the pieces take them off and put them back together before they learn . It all depends on the type of student you are teaching .
You are This Old House crew worthy. Great job, great speaking voice. You'd be great on their show. This is exactly how they explain things & why i love it. You've got another new follower in me. Great job, keep it up! 👏👏👏
Craig, you have wonderful videos for those coming up into the HVAC/R trade. Well explained . I’ve been in the trade over 30 years, and I’ve gotta say this is good stuff. Keep up the good work and happy new year!!!
Thanks Craig! This will help me fix my gas furnace that won’t stay lit for more than a few seconds. It’s probably the flame rod not sensing flame and either needs cleaning or replacing, but now I know how to test the flame rod, thanks to you. URDB (you are dee best!) :)
I'm curious about the voltage on the flame rod, when we test flame rods in the field we always measure the signal from the rod in Microamps DC, I didn't realize there was also A/C voltage on the flame rod, so the signal from the flame rod to the board is measured in microamps, DC, but the rod also has a potentially high A/C voltage on it? Could you share more about this?
It is flame rectification. I know I'm not explaining this by the book, but basically, the AC voltage present on the flame rod is rectified by the flame to DC. It is just a phenomenon that happens when AC voltage is in a flame. The flame conducts a very small amount of DC current to ground, this is the uA DC that we measure. This is why the ground on a furnace is just as important as the hot and neutral. Also, rusty burners can inhibit the current flow. 14:30 Craig explains this pretty well.
@@coolramone the way I understand it is : there is AC power (different than voltage) available to the flame rod. When the circuit is closed by the flame, the AC power is rectified by the flame to a small DC circuit which can be measured in micro amps. The flame is the switch.
Having issues with my raypak pool heater. I have identified it down to a flame rectification issue as the pilot lights well and doesn’t activate the main gas valve for burners. Today I attempted to test the negative for micro amps (disconnected from gas valve) I connected it in series and couldn’t get a micro amp reading. When unplugging I got electrocuted by touching one probe of the multimeter when the positive was plugged into the negative. Why would the negative be carrying an electrical charge from the motherboard? Thanks
I had a headache yesterday with a direct spark ignition furnace, except it had a pilot ignition assembly with a single flame rod. The ground wire was hanging on by a thread & was enough to not not give it proper ground. Also the pressure switch was constantly opening and closing since the inducer is on its was out only pulling .67” of WC on a .70” WC switch. The arching from the spark ignition due to the opening/closing of the pressure switch I think may have caused the pilot assembly ground to fail? 🤷
I was troubleshooting a lochinvar water heater. Same principle though, what happening is it will prepurge and trial for ignition again and again. What should be the problem? No flashes
I'm getting a voltage drop in the MC terminal, when the wire is connected to the gas valve it is only reading 15vac however when it is disconnected from the gas valve it reads 26vac. The pilot is sparking and lighting and blower is turning on however this drop in voltage seems to be preventing the burners from coming on. Would it be the gas valve or the ignition control module at fault?
If the module go bad and need to be replaced should we have to look the same one or there is an universal will work with all models ? And it needs to do some changes or just we can put it direct without any changes thanks in advance
Hi my furnace always had at least 1 click I hear before start up and fan kicking on but lately I been hearing 2-3 clicks/Spark before the blower motor kicks on is that normal ? Same clicks I hear in your video at 8:16 but yours clicks/sparks much more .
Good morning, excellent explanation and I like your videos, you know a lot, I have a question about my furnice, when it calls to turn on the sparks it clicks for 30 or 40 seconds and it turns on and works well, what could be the reason, thank you
Soo.. since my boiler does not have a "sense", that flame rod is the same as the spark ? So that current is happening through the spark and thats why it has spark/sense?
When the AC voltage is sent down for the sparking across the the probes(or probe and burner ) to the ground to make the circuit , the flame sensing probe is also sending ac down to the flame to convert to DC for same ground to prove? Is the flame rectification proven after the sparking stops , like a window of time ? As it would be AC from the spark and DC from the flame proving or am I getting confused ? Or is it possible to sense both at the same time from the same ground ? Anyone’s insight is helpful tia
Great video! I have a Rheem direct spark ignition unit. The unit would short cycle where the burner would light and burn for about 4 seconds then shut off. After a few attempts, it wouldn't do anything for about an hour. I couldn't call anyone because of my work schedule and it being a holiday week also. I took a shot and ordered a new dual electrode spark ignitor from Amazon, which showed up in only 2 days. After I installed it, my heater works perfectly. Was this just a coincidence or does the spark ignitor have something to do with the flame rectification process? (it was labeled ignitor/flame sensor) Thank you.
The only clarification I would offer is flame sensing microamps (ua) is present on the sense wire as well as the ground wire. You need both to complete the circuit.
My furnace has a control board for everything. The inducer fan goes, the spark ignitor clicks, the gas valve opens in short few second spurts a few times but it won't light. While doing this the furnace clunks or clicks like a gas valve or relay. The best I can gather it's a rusty buner tube not getting ma back to ground or a bad ground and it cutting the gas quickly then retrying a few times before giving up for a few minutes. The part I don't understand is why the clunking or clicking. The furnace doesn't do this all the time just sometimes.
A flame rollout that is constantly tripping is usually a sign of a cracked heat exchanger and is very bad news. These switches are generally very reliable so you'd be fortunate if a replacement solved your issue. A CO detector near the burners when it's running might show high CO as would a washy flame pattern that rolls out when the main blower powers on.
A couple months ago we installed a 95% Ruud furnace.It is now rusting very bad , the inside of the inducer collected some orangish rust. Even drain coming out is orange/rusty. Has correct gas pressure. Has both exhaust and intake going outside. RUUD Model # R95TC0701317MSA
I have a question ?? Is there a device tool that a Hvac tech can u to plug on fan motor’s n control board to get a diagnosis besides a (multi meter ) to test all components
@@mr.spliffaddikts9548 The short answer is no, not really. Most furnaces for the last 30 years do have some sort of onboard diagnostics. When there is a problem, we count blinking lights on the control board and then find the key to what the blinking lights mean to narrow our search for the problem. However, some upper-end units do have more sophisticated means of diagnosing the issue. I service WaterFurnace geothermal units and use an Aid-Tool analyzer on the 3 Series and 5 Series units. Apparently, the 7 Series units can be diagnosed through an internet connection, but I have no direct experience with them. The analyzer can provide a lot of information about how the unit is operating and what issues it might have had or is currently having. Much better than blinking lights.
I've been looking for a video like this! As always, your explanations are clear and succinct. Thank you! Do you by chance have a book where you detail this?
The GND wire that connects to the frame of the burners is the Return Path for the Spark electricity. Every electric energy flow requires a complete circle path... a spark is no different. It's just like a car spark plug... if you connect the ignition wire to the spark plug - but don't connect the metal threads to the spark plug to the Chassis or Engine Ground, you won't get a spark across the spark plug. If the spark generator board isn't Grounded to the burner metalwork, it could burn up the spark generator - because that high voltage energy pulse HAS to have a return path... and if it's not through the proper path, it WILL create a non-desired return path... usually through the High Voltage transformer on the circuit board... which usually causes a failure.
A few questions: The Gas Unit heater at the warehouse is not working. Why is the automatic ignition system not working two times? The LED light was out. I tested the 120V to 24Vac transformer, which is working. What is it not working cause? is it overload? limit switch or valve gas fail? or did the automatic ignitor system have a problem? it name is FENWAL. now it is discontinued. hard get order it because FENWAL company is gone. KIDDE-FEWNELL is a new company. Maybe I am wrong.
Here is a great video that goes into detail about the flame rectification physics and how flames can act as a diode that basically makes a half wave rectifier -> ruclips.net/video/FjrzbqFDnAw/видео.html
![Noob To Max With DRAGON REWORK In Blox Fruits [FULL MOVIE]](http://i.ytimg.com/vi/LnBMOinoOvA/mqdefault.jpg)
I always double check power. Great stuff, my company doesn’t teach this stuff, glad i can learn on here!
Isn't that sad
There comes a point where you as a tech must educate yourself. Don't wait or expect any company to get you there.. Trust me! They wont
Most don’t because of high turnover, takes away profits and they’ll just be teaching their future competition.
No need to look any further for a video covering direct spark ignition furnaces. This is the holy grail. Very thoughtful and thorough presentation.
Great videos as always. Well explained and I love the way you laid out all your components. This helps all of us a lot. Keep up the good work as always!
I love the way you teach! Your wording is on point. Hands on is the cherry on top!
Craig you are going to need a furnace book to complete the set of books you already have and your videos then act as a great complement. Always well explained and laid out.
Thank you so much!!! That last book took two years!
@@acservicetechchannel anything good always takes time and effort to plan and then write.
I wish training videos like this were available when I was a kid since my dad forced me to learn at the age of 12 and we had to order books through snail mail or request our local library to order them which would take 5 to 8 weeks for delivery. Back before the Internet was invented..
Greetings👋. Do this mean anybody can service their own furnaces? I dont like that prospect.
Better that way because you really learn compared to this I’ll learn and forget just because it was too simple
@@THExBIGxBADxWOLF93 it good for the simple ones who get over whelmed seen too many things that are spread out .
Some students learn better when everything is like on one page in front of them .
Have to teach different types of students learning abilities differently.
Some students can learn just by reading words without ever seen an actual furnace .
Other students literally have to put their hands on the pieces take them off and put them back together before they learn .
It all depends on the type of student you are teaching .
Awsome , every heating service should view this,thanks.
Awesome setup man! I love the teaching setups you make.
Great video Craig and very thorough.
You are This Old House crew worthy. Great job, great speaking voice. You'd be great on their show. This is exactly how they explain things & why i love it. You've got another new follower in me. Great job, keep it up! 👏👏👏
Craig, you have wonderful videos for those coming up into the HVAC/R trade. Well explained . I’ve been in the trade over 30 years, and I’ve gotta say this is good stuff. Keep up the good work and happy new year!!!
Thanks so much Johnny!!!
Thanks a lot your channel is gold for technicians like me to expand their knowledge and skills to serve our customers better
Thanks!
Thanjks so much German!
Great video Craig. Thank you.
Thanks Craig! This will help me fix my gas furnace that won’t stay lit for more than a few seconds. It’s probably the flame rod not sensing flame and either needs cleaning or replacing, but now I know how to test the flame rod, thanks to you. URDB (you are dee best!) :)
Clean the flame sensor
Rarely will you replace a fs
Great video, very well organized and laid out. Great lab setup.
Craig, once again a great explanation! Thank you so much. You explain things so precise and simple. Love the video.
Amazing job explaining the operation of a spark ignition. Thank you boss man!
very beautifully explained
Once again, excellent explanation. Thanks for sharing.
Great experience with good explanations
Great illustration. Thank you!
I really love your classes, Thank you.
You're very welcome! Thank you for enjoying our content!
Love this guy! Thank you for making this video
Excellent tutorial. Great video! Thank you
Good video thanks Craig
Gracias!! Well explained
Is there a step up transformer inside that board to be able to send 120 vac to the flame sensor?
120v is present at the board and it doesn’t require a step-up transformer.
I'm curious about the voltage on the flame rod, when we test flame rods in the field we always measure the signal from the rod in Microamps DC, I didn't realize there was also A/C voltage on the flame rod, so the signal from the flame rod to the board is measured in microamps, DC, but the rod also has a potentially high A/C voltage on it? Could you share more about this?
It is flame rectification. I know I'm not explaining this by the book, but basically, the AC voltage present on the flame rod is rectified by the flame to DC. It is just a phenomenon that happens when AC voltage is in a flame. The flame conducts a very small amount of DC current to ground, this is the uA DC that we measure. This is why the ground on a furnace is just as important as the hot and neutral. Also, rusty burners can inhibit the current flow. 14:30 Craig explains this pretty well.
@@chrisdeanndavison3626 Thanks! My fault for posting the question before finishing the video.
So there are ac micro amps AND dc micro amps running through the flame rod, and which one is being measured by the pc board, ac or dc?
@@coolramone the way I understand it is : there is AC power (different than voltage) available to the flame rod. When the circuit is closed by the flame, the AC power is rectified by the flame to a small DC circuit which can be measured in micro amps. The flame is the switch.
@@coolramone dc microamps
24V into the ignition module but 120V out to the sense wire. Is there a step-up transformer in the module? Am I missing something?
i mean it also provides 10000 volts for the ignitor. was curious about this as well. has to be something internal in the ignition control
Having issues with my raypak pool heater. I have identified it down to a flame rectification issue as the pilot lights well and doesn’t activate the main gas valve for burners. Today I attempted to test the negative for micro amps (disconnected from gas valve) I connected it in series and couldn’t get a micro amp reading. When unplugging I got electrocuted by touching one probe of the multimeter when the positive was plugged into the negative. Why would the negative be carrying an electrical charge from the motherboard? Thanks
Another excellent video. Thanks
Wow! Very good video!
Great video!!! I wish if you would have a video about domino’s pizza chain oven, thank you Craig and happy new year 2023🎉
beautiful video
I had a headache yesterday with a direct spark ignition furnace, except it had a pilot ignition assembly with a single flame rod.
The ground wire was hanging on by a thread & was enough to not not give it proper ground.
Also the pressure switch was constantly opening and closing since the inducer is on its was out only pulling .67” of WC on a .70” WC switch.
The arching from the spark ignition due to the opening/closing of the pressure switch I think may have caused the pilot assembly ground to fail? 🤷
I was troubleshooting a lochinvar water heater. Same principle though, what happening is it will prepurge and trial for ignition again and again. What should be the problem? No flashes
I'm getting a voltage drop in the MC terminal, when the wire is connected to the gas valve it is only reading 15vac however when it is disconnected from the gas valve it reads 26vac. The pilot is sparking and lighting and blower is turning on however this drop in voltage seems to be preventing the burners from coming on. Would it be the gas valve or the ignition control module at fault?
If the module go bad and need to be replaced should we have to look the same one or there is an universal will work with all models ? And it needs to do some changes or just we can put it direct without any changes thanks in advance
Hi my furnace always had at least 1 click I hear before start up and fan kicking on but lately I been hearing 2-3 clicks/Spark before the blower motor kicks on is that normal ? Same clicks I hear in your video at 8:16 but yours clicks/sparks much more .
hit it with soft sand paper
Good morning, excellent explanation and I like your videos, you know a lot, I have a question about my furnice, when it calls to turn on the sparks it clicks for 30 or 40 seconds and it turns on and works well, what could be the reason, thank you
Excellent video as always!
Great video! Thanks
Great video
Thanks a lot 🙏
Thank you for upload
Soo.. since my boiler does not have a "sense", that flame rod is the same as the spark ? So that current is happening through the spark and thats why it has spark/sense?
Is it possible the flame sensor is bad and wouldnt let my HSI igniter to glow?
Craig I have a stupid question
If there is only 24 V going to the ignition module, how does it produce high voltage?
There is a low voltage to high voltage transformer under the hood of the icm.
When the AC voltage is sent down for the sparking across the the probes(or probe and burner ) to the ground to make the circuit , the flame sensing probe is also sending ac down to the flame to convert to DC for same ground to prove? Is the flame rectification proven after the sparking stops , like a window of time ? As it would be AC from the spark and DC from the flame proving or am I getting confused ? Or is it possible to sense both at the same time from the same ground ? Anyone’s insight is helpful tia
8:17
My old 1986 System does not seem to have a flame rod. It just has the old school honywell intermittent igniter and sparker and the fan limit switch.
Great video! I have a Rheem direct spark ignition unit. The unit would short cycle where the burner would light and burn for about 4 seconds then shut off. After a few attempts, it wouldn't do anything for about an hour. I couldn't call anyone because of my work schedule and it being a holiday week also. I took a shot and ordered a new dual electrode spark ignitor from Amazon, which showed up in only 2 days. After I installed it, my heater works perfectly. Was this just a coincidence or does the spark ignitor have something to do with the flame rectification process? (it was labeled ignitor/flame sensor) Thank you.
They sometimes are combined with a third rod coming in front of the burner as the flame rod. The older Airease units are that way also.
Great video.
Can you make a video explaining common/neutral wires. What they are, why they are there and what they do?
Does this apply to hsi ignitors as well?
The only clarification I would offer is flame sensing microamps (ua) is present on the sense wire as well as the ground wire. You need both to complete the circuit.
True, and I believe Craig covered this starting at about 8:00 through 10:00.
Great job sir 😘🙏
My furnace has a control board for everything.
The inducer fan goes, the spark ignitor clicks, the gas valve opens in short few second spurts a few times but it won't light. While doing this the furnace clunks or clicks like a gas valve or relay.
The best I can gather it's a rusty buner tube not getting ma back to ground or a bad ground and it cutting the gas quickly then retrying a few times before giving up for a few minutes.
The part I don't understand is why the clunking or clicking.
The furnace doesn't do this all the time just sometimes.
great video…suggest more video about intermittrnt gas valve with ignition control…thanks anyway
What about a faulty module? How can you troubleshoot for that
Thanks nice and clear
Flame roll out switch, cannot find a replacement for mine, keeps tripping can you help me find a replacement for it? Thank you
A flame rollout that is constantly tripping is usually a sign of a cracked heat exchanger and is very bad news. These switches are generally very reliable so you'd be fortunate if a replacement solved your issue. A CO detector near the burners when it's running might show high CO as would a washy flame pattern that rolls out when the main blower powers on.
A couple months ago we installed a 95% Ruud furnace.It is now rusting very bad , the inside of the inducer collected some orangish rust. Even drain coming out is orange/rusty. Has correct gas pressure. Has both exhaust and intake going outside. RUUD Model # R95TC0701317MSA
Proper duct sizing?
why does a new ds845 dont have a terminal for fame sense anymore? the one you have still have one, but if i google for a new one it doesnt
Where can I buy the spark igniter wire?
Excelente muy bien Gracias
exelent videos !!!
I have a question ?? Is there a device tool that a Hvac tech can u to plug on fan motor’s n control board to get a diagnosis besides a (multi meter ) to test all components
It’s there any please link it to the comment section please n thank
@@mr.spliffaddikts9548 The short answer is no, not really. Most furnaces for the last 30 years do have some sort of onboard diagnostics. When there is a problem, we count blinking lights on the control board and then find the key to what the blinking lights mean to narrow our search for the problem. However, some upper-end units do have more sophisticated means of diagnosing the issue. I service WaterFurnace geothermal units and use an Aid-Tool analyzer on the 3 Series and 5 Series units. Apparently, the 7 Series units can be diagnosed through an internet connection, but I have no direct experience with them. The analyzer can provide a lot of information about how the unit is operating and what issues it might have had or is currently having. Much better than blinking lights.
Are there manufactures who are still using DSI. I thought everyone had switched over to HSI quite a while ago.
Almost all manufacturers use it for outdoor package units, thanks!
I've been looking for a video like this! As always, your explanations are clear and succinct. Thank you! Do you by chance have a book where you detail this?
Thank you so much
The GND wire that connects to the frame of the burners is the Return Path for the Spark electricity.
Every electric energy flow requires a complete circle path... a spark is no different. It's just like a car spark plug... if you connect the ignition wire to the spark plug - but don't connect the metal threads to the spark plug to the Chassis or Engine Ground, you won't get a spark across the spark plug.
If the spark generator board isn't Grounded to the burner metalwork, it could burn up the spark generator - because that high voltage energy pulse HAS to have a return path... and if it's not through the proper path, it WILL create a non-desired return path... usually through the High Voltage transformer on the circuit board... which usually causes a failure.
How does it get up to 10000 volts?
Frankenfurnace by AC Service tech!
Awaiting UL approval...
Thanks
hello, can you provide Polisz subtitles on your channel
A few questions: The Gas Unit heater at the warehouse is not working. Why is the automatic ignition system not working two times? The LED light was out. I tested the 120V to 24Vac transformer, which is working. What is it not working cause? is it overload? limit switch or valve gas fail? or did the automatic ignitor system have a problem? it name is FENWAL. now it is discontinued. hard get order it because FENWAL company is gone. KIDDE-FEWNELL is a new company. Maybe I am wrong.
BRAVOOOO!
Or why would it keep tripping?
👏👏👏
bad camera angle but good video
I didn't know they made these, but was just thinking what a waste of power the old glow ingiters waste.
Here is a great video that goes into detail about the flame rectification physics and how flames can act as a diode that basically makes a half wave rectifier ->
ruclips.net/video/FjrzbqFDnAw/видео.html
Additionally, looking into Townsend Discharge is an interesting physics rabbit hole.
Great video !! Thank you