Thanks... the repair company wanted to charge 1500 for repair or just replace the entire unit which was the ultimate goal for him. This video fixed the small problem free.
Just an update from Lennox. They don't warranty if you want to be proactive. If you DIY your pressure switch because there is a problem and then phone the company for warranty they will not warranty the switch. So let your house freeze, pipes burst, etc. then phone the company even though you know that there is a problem.
Thank you! We try to make all of our videos helpful, detailed and easy to follow. If you're curious we recently released a series on how gas water heaters work, including some pretty detailed animations: ruclips.net/video/BHUPFLbb8NY/видео.html Just thought you would find it interesting!
Need clarification please - If the same two wires that went to the switch are connected back to the same switch, does it matter which wire goes to which terminal?
Thanks for watching. A switch simply connects and disconnects power within a circuit. It does not matter which wire is connected out of the 2 wires, it will not change how this switch works.
Thanks for this video, the animation helped be troubleshoot why my furnace was tripping on the pressure switch...leaves had plugged up a strainer on the inlet line to the little exhaust blower. Saved me time and $$$!
You're welcome Matt, we're glad that you found the animation and the video helpful! There are many things that can plug the inlet vent to the inducer, leaves and even ice are quite common.
Thanks for stopping by again. Without special equipment it's difficult to test the switch. You can learn more about these switches here: ruclips.net/video/Mdu7QlAzWOg/видео.html So to answer your question there isn't a quick easy way to safety verify which switch has failed.
I have a Trane XR90 furnace. I cleaned P trap and all pipes connected to the switch but the furnace still won't light. I sucked the pressure switch and heard one click, and heard another one when I stop sucking. Do you think I should replace the pressure switch? If I choose a new pressure switch, I will make sure its pressure rating matches the old one, but are there any other parameters that should match? Thank you.
If you want to know if its a problem with the pressure switch you can check your furnace codes. You can learn more here ruclips.net/video/qRmNrmjKEyk/видео.htmlm10s For matching pressure switches, the pressure rating is the most important, and but check to see if its a PF (pressure fall) or a PR (pressure rise) switch. Most are PF. Its best get a match based on your part number, as the mounting holes can be different with some switches. When in doubt, take the pressure switch out and bring it in store to use as a reference. Hope this helps.
Thank you for you reply. The furnace code indicates pressure switch error. The pressure switch is 1.4“ WC, but doesn't indicate whether it is a PF or PR. I tried to buy the same part but could not find it anywhere except used ones.
You're welcome. The WC is the measurement of inches of water column raised, its just the way pressure switches are rated. In furnaces almost all are PF switches, so if it doesn't specifically say, then its likely a PF. We carry a few pressure switches which you can browse here www.amresupply.com/catalog/Switches-HK3Z If you can't find a match, there are universal switches that are adjustable www.amresupply.com/part/9397688 There's a PDF below the part with more detail on how to adjust.
Thanks for watching. Water can accumulate inside a high efficiency furnace as these condense water vapor to extract more heat from combustion. Check to make sure the water is draining properly, and that there are no pinched or blocked lines. As well condensate could form inside of the exhaust vents, so make sure that nothing is restricting the vent on the outside of your home.
Thanks for the video. I wanted to know if the pressure switches have a finite service life. I was told by one technician that i should not wait for them to fail, but replace them as a maintenance item. My furnace is almost ten years old. What is your opinion on this?
You're welcome, we're glad that you found it helpful. Pressure switches and limit switches have internal components that flex or move. These are good to a certain number of cycles and given enough time they will fail or simply lose sensitivity. Some switches will last longer than other and some will fail early. Replacing them early as part of maintenance doesn't hurt and will give you peace of mind.
You're welcome, we're glad you found the video helpful! In most models, disconnecting power to the furnace for more than 30 seconds will clear the control board and reset it. There are some differences between manufactures though. If that doesn't work, find your furnace model number and do a search for that directly.
Hi 5Riversz, that's a good question! The wiring on the pressure switch doesn't affect the switch. You can swap the wires and the switch will still function the same.
Thanks for watching. There are a lot of part numbers and number systems so I'm not sure. D/C is often used to describe direct current. W/C is likely referring to the pressure in "water columns" Do the other specifications line up? Can you match by any other ratings?
@@AmreSupply my furnace is 8 year old u think it's time to change it. I had a guy came to look at it he say the flame sensor and the pressure switch is bad. He say I should get a new furnace. Can u advise me on this thank you
@@srla.5145 Most furnaces should last 15 - 20 years with some maintenance. The flame sensor can accessd and cleaned quite easily: ruclips.net/video/af_qRnfHFws/видео.html As well the pressure switch is simple to replace. Start with those parts before replacing the entire furnace. Two faulty parts is not indicative of a bad furnace. For example you wouldn't scrap a car just because the alternator failed, when it has a perfectly healthy engine.
Hi Jamie, great question. The white cap on the switch port is just used just to differentiate one port from the other. Some have a white and red caps www.amresupply.com/part/12129054 and some switches use different color plastics in the switch body www.amresupply.com/part/12657129 Overall as long as you match the same port as before than you're in the clear.
Anyone know if a 'goodman' brans pressure switch will work in a 'lennox' furnace? They look very similar & amazon brought it up in the search. Any info would be helpful
Thanks for watching. Furnaces use switches and motors which often come from a variety of manufacturers. When finding a replacement there are often crossover parts. Just make sure to match the physical size and the rated specifications.
Does it matter which wire goes on which tab? I bought one with the same part # as the old one but the tabs are situated differently & both tabs are the same size so I'm concerned about connecting it backwards.
Thanks for watching. When it comes to these switches, they are not effected by polarity, they simply connect or disconnect power within a circuit. It doesn't matter which connector attaches to either of the 2 terminals, it will work either way.
so it doesn't matter which wire is connected to which terminal. What if my furnace has 2 switches? there is a "jumper" wire that goes from one switch to the other? I'm a little confused. thanks @@AmreSupply
thanks for the information, I have an older tridelta pressure switch with a purple wire and brown wire running to it in a Rheem 90+ updraft furnace, how to I tell which wire is common? and which is npc, thanks
Hi Cliff Harmon, always check your manual if you want to narrow down what each wire is but in this case reversing the wires will not affect the function of this switch. As long as you connect the same wires as before, than everything should work.
thanks, I did chase down the wires on the schematic but goes to a nine pin block and cant seem to find schematic for the 9 pine connector, howwever the purple wire is hot all the time so assume this is the hot, brown is COM
Hi Vance I have a Bryant 95s evolution. The furnace fan will not start but I can spin the fan motor manually and the fan goes and the heat comes on any ideas
Hi Stephen, thanks for watching. If manually spinning the fan causes it to work, then it likely has a failed capacitor. Capacitors are used with some motors and are needed to start the motor. This can be tested with a multimeter as shown here: ruclips.net/video/NkgxNLCrmr0/видео.html If the capacitor has failed, then replacing the capacitor will allow the fan to start normally.
@@stephendinger7114 Yes you are right that setting the thermostat to FAN will run the blower fan without igniting the burners (this setting is commonly used to just circulate air around the home between heating cycles) The inducer fan will only run when there is a call for heat so a faulty inducer capacitor won't affect things when you're just circulating air with the FAN setting.
We have an older furnace with a failing TriDelta Industries pressure switch. We had it diaged by a company but are not going to pay the astronomical fee to have them replace it. Replacing it looks straightforward enough, our only issue is, how do we find a replacement part for it when it's been discontinued? Our part number is FS4080-85. Any help would be greatly appreciated!
Thanks for watching. First look around for an exact match. Sometimes a part like that is still carried by some local HVAC shops but check online as well. That part number doesn't show up in our system but if needed you can always use a universal pressure switch. You would simply need to match the terminals and set the universal switch to match the pressure rating. The pressure rating is in inches of water column and might show something like 0.5" WC. You'll want to match this exactly. As well make note of which terminals your original switch has and connect those on the new switch. The terminals are listed NO for normally open, NC for normally closed and COM for common. ruclips.net/video/yug_UfBUsec/видео.html You can see a universal switch here; www.amresupply.com/part/9397688
My furnace randomly decides to turn on with a louder than normal inducer fan. Sounds like the inducer fan is starting in stage 2, instead of stage 1. When it does this, the furnace will turn off a few seconds after the hot surface igniter turns on, but just before the burners light. Would a faulty pressure switch cause this?
Hi Shawn, thank you for watching. A faulty pressure switch could cause this behavior. It can be helpful to check to see if your furnace is giving you any codes. These specific codes will be listed in the furnace manual or on a chart on the side of the door. The codes and the sequence of operation are both talked about here: ruclips.net/video/b0sAGt-1niU/видео.html
@@AmreSupply thanks for the reply. No codes are shown when this behavior happens, except for the normal a875 code. I ordered a new flame sensor and a pressure switch (hi/low). If this doesn't resolve it, what else could be causing this? Gas valve I guess?
@@Shawn855 Yes you are right that a faulty gas valve could create this problem as well. Definitely its smart to replace any small sensors or switches before replacing anything more extensive.
Thank you for watching. The colors of the wires are often different in various models of furnaces. Best thing to do is to take a picture before disconnecting, and replace the same color on the same terminal it originated on.
Does it matter which wire goes to each terminal on the pressure switch ? I noticed one terminal says "com" the other says "on nc" I assume the "com" is the common or ground? and the other is where the hot wire goes?
Hi scientificfighting1, you are right that the "com" terminal is the common wire and that the hot wire should go to the "nc" terminal. The "nc" refers to "normally closed" which means that the switch is closed when the furnace is running, and the switch will open when the pressure is low.
Hi scientificfighting1, just to clarify even though these switches may list "NC" and "COM" if you reverse the wires it will not affect the function of the pressure switch. As long as you connect the same wires as before, then everything should work.
Let me make sure I understand...if the same two wires that went to each switch are connected back to the same switch it doesn't matter which wire goes to which terminal as long as the same two wires are used ?
Hi Sanford, If its saying "open top airflow" and if you can verify that your pressure switch is tripping (furnace inducer fan runs but the furnace won't ignite) then check to see if there is adequate airflow in the heat exchanger, flue vent, and inducer and see if anything is blocking the airflow. If the airflow is good then the pressure switch could be faulty.
Thanks for watching. It depends on how far into the sequence your furnace gets before stopping. This video covers all the different issues in the sequence: ruclips.net/video/b0sAGt-1niU/видео.html Now if the Furnace stops before ignition, but the pressure switch is good, then it could be an issue with the airflow. This can be harder to narrow down and can be helpful to get it inspected by an HVAC technician.
Thanks for watching. The inducer pushes the exhaust out of the system. Not all furnaces are configured the same but there will be negative pressure before the inducer fan and positive pressure after it.
Translations into spanish aren't planned anytime soon. You can use the auto translate button on youtube. Las traducciones al español no están planeadas pronto. Puede usar el botón de traducción automática en youtube.
Hi Ramon. These pressure switches are meant to protect the furnace, so if you bypassed the switch and the sequence continues it either means the switch is bad.... or that the pressure inside the heat exchanger is too low for safe combustion. Just a note its not recommended to run the furnace continuously with anything bypassed. If you replace the pressure switch and the ignitor still doesn't light, then that will prove that its a problem with the pressure. This can be caused by a blockage in the pressure switch tubing (causing the pressure switch to think the pressure isn't good) or a blockage in the inducer motor port or flue vent. Hope this helps.
I ordered a new pressure switch by looking up the part #, but I didnt realize until I was getting ready to install it that the old part -0.35 PF and the new one is -0.30. How critical is this?
Thanks for watching. PF means pressure fall, and a lower rated switch will change how sensitive the switch is which can change how the furnace operates. We always recommend matching exactly but there are some cases where a certain range tolerance still works. Can't recommend for sure without seeing the system in it's entirety.
@@corey977 A different rated switch has the risk of the furnace shutting down within different parameters which is why we can't recommend using anything other than a match. As well depending on where you got the switch there are often no returns after installation, so once you install it, you're stuck with it.
Thanks for watching. These were some of the earlier videos we made and we do go into a bit more detail in others. If you want to know how the pressure switch works we have a video on appliance components. I have liked the section on switches: ruclips.net/video/Mdu7QlAzWOg/видео.html
@@AmreSupply thanks. I was looking for more explanation on how the vacuum part works. where vacuum is and where pressure is. I knew my switch was good but the furnace would not turn on. I have been bypassing it for over a year, it is just a shop furnace and not used often. It is a single switch with 2 ports, one connected to the heat exchanger area and the other to the condensate trap. Turns out the hoses at the switch were swapped and giving the wrong signal to the switch. I did not find a diagnostic that would have caught this. And I don't have a in of water meter to measure the low pressure and vacuum being used. But this got my brain going and I was able to figure it out. I did learn how to tell how much the switch needed to trigger from your video.
I have a Trane XB Propane Furnace (2009) that will not light unless I tap on the air intake tube. I cleaned the flame sensor with steel wool. I've checked the pressure switch with your "soda straw" method, and I hear the 2 clicks. However, I suppose the switch could still be the problem. The inducer fan blows air, The ignitor glows, but the gas doesn't ignite. I don't have professional HVAC test tools, so I'm hoping I can fix this by simply replacing the pressure switch or ignitor. Here is a video I made of the issue: ruclips.net/video/QLoN2bT9MJE/видео.html
You shouldn't encourage people who don't know what they're doing to start digging around in their furnace. Not only could it be potentially very dangerous, but you are also selling the HVAC industry down the toilet.
Hi M.A. thank you for your feedback. There are countless DIY blogs, and videos on the internet explaining how to troubleshoot furnaces. Homeowners who are inclined to understand and troubleshoot their furnace will jump into it regardless and will research it on their own. We feel its important to provide solid information which also reinforces the overall safety. Given this there are still many people that will see a video, will see how it works, and will decide to call a professional. With a better understanding of the furnace this helps them communicate their problem to to a technician. Also any knowledge learned also protects the homeowner against any potential fraud as there are small number of non-reputable "professionals" who are quick to take advantage of someones lack of understanding of how a furnace works. Its no different than car maintenance. Any consumer can buy parts for any model of car. There are some fixes that are simple and can be done in 30 min by anyone, but there are many repairs that are best done with the tools and knowledge that only professionals have.
As a homeowner, I have had the same issue on my furnace almost annually and I appreciate being able to get solid information so that I don't have to wait a week for a repair person, not only that, my furnace went out at 3 am in northern Minnesota at 38 below and if I wouldn't have found this information, I would've been in serious trouble. Thanks to these guys giving us ideas to temporarily remedy the issue I was able to blow into my pressure switch and my furnace started back up!
@@themythhunter9764 Thanks for sharing your experience! We have some extremely cold months in Canada and even a few hours without a furnace running can quickly add up so we understand your situation. We're glad this video helped you get your furnace running again!
Thanks... the repair company wanted to charge 1500 for repair or just replace the entire unit which was the ultimate goal for him. This video fixed the small problem free.
You're welcome!
Extremely clear and informative. Thank you
You're welcome you Dave! We're glad you found it helpful!
Just an update from Lennox. They don't warranty if you want to be proactive. If you DIY your pressure switch because there is a problem and then phone the company for warranty they will not warranty the switch. So let your house freeze, pipes burst, etc. then phone the company even though you know that there is a problem.
It was quite helpful. Thank you for the upload.
You're welcome Jamal, we're just happy to help!
fixed mine by blowing and sucking into the hoses for about half a minute, fixed the problem.
Thanks for watching. We're glad you were able to fix the problem!
You can damage the switch by doing that. The suction or blowing pressure ought to be within the limits and its easy to reach the limit
Wow! STRAIGHT FORWARD...
Other channels take note how a tutorial is done!
Thank you! We try to make all of our videos helpful, detailed and easy to follow. If you're curious we recently released a series on how gas water heaters work, including some pretty detailed animations: ruclips.net/video/BHUPFLbb8NY/видео.html Just thought you would find it interesting!
Need clarification please - If the same two wires that went to the switch are connected back to the same switch, does it matter which wire goes to which terminal?
Thanks for watching. A switch simply connects and disconnects power within a circuit. It does not matter which wire is connected out of the 2 wires, it will not change how this switch works.
Thanks for this video, the animation helped be troubleshoot why my furnace was tripping on the pressure switch...leaves had plugged up a strainer on the inlet line to the little exhaust blower. Saved me time and $$$!
You're welcome Matt, we're glad that you found the animation and the video helpful! There are many things that can plug the inlet vent to the inducer, leaves and even ice are quite common.
Hi once again. Sir it is showing 2 pressure switch in your video. How do we know that which one we have to replace.?
Thanks for stopping by again. Without special equipment it's difficult to test the switch. You can learn more about these switches here: ruclips.net/video/Mdu7QlAzWOg/видео.html
So to answer your question there isn't a quick easy way to safety verify which switch has failed.
I have a Trane XR90 furnace. I cleaned P trap and all pipes connected to the switch but the furnace still won't light. I sucked the pressure switch and heard one click, and heard another one when I stop sucking. Do you think I should replace the pressure switch? If I choose a new pressure switch, I will make sure its pressure rating matches the old one, but are there any other parameters that should match? Thank you.
If you want to know if its a problem with the pressure switch you can check your furnace codes. You can learn more here ruclips.net/video/qRmNrmjKEyk/видео.htmlm10s For matching pressure switches, the pressure rating is the most important, and but check to see if its a PF (pressure fall) or a PR (pressure rise) switch. Most are PF. Its best get a match based on your part number, as the mounting holes can be different with some switches. When in doubt, take the pressure switch out and bring it in store to use as a reference. Hope this helps.
Thank you for you reply. The furnace code indicates pressure switch error. The pressure switch is 1.4“ WC, but doesn't indicate whether it is a PF or PR. I tried to buy the same part but could not find it anywhere except used ones.
You're welcome. The WC is the measurement of inches of water column raised, its just the way pressure switches are rated. In furnaces almost all are PF switches, so if it doesn't specifically say, then its likely a PF. We carry a few pressure switches which you can browse here www.amresupply.com/catalog/Switches-HK3Z
If you can't find a match, there are universal switches that are adjustable www.amresupply.com/part/9397688 There's a PDF below the part with more detail on how to adjust.
One question, why does it leak water? inside The cure cause could be the pressure switch?
Thanks for watching. Water can accumulate inside a high efficiency furnace as these condense water vapor to extract more heat from combustion. Check to make sure the water is draining properly, and that there are no pinched or blocked lines. As well condensate could form inside of the exhaust vents, so make sure that nothing is restricting the vent on the outside of your home.
Thanks for the video. I wanted to know if the pressure switches have a finite service life. I was told by one technician that i should not wait for them to fail, but replace them as a maintenance item. My furnace is almost ten years old. What is your opinion on this?
You're welcome, we're glad that you found it helpful. Pressure switches and limit switches have internal components that flex or move. These are good to a certain number of cycles and given enough time they will fail or simply lose sensitivity. Some switches will last longer than other and some will fail early. Replacing them early as part of maintenance doesn't hurt and will give you peace of mind.
If the control board has a lockout, do you have to reset it? If so, how? Thank you very much for the video.
I'm definitely no expert; maybe try turning off and on the power switch?
You're welcome, we're glad you found the video helpful! In most models, disconnecting power to the furnace for more than 30 seconds will clear the control board and reset it. There are some differences between manufactures though. If that doesn't work, find your furnace model number and do a search for that directly.
Thank you everyone for the reply. I will follow as such when I received my pressure switch.
What happens if the wires on the pressure switch are mixed up as both of my wires are yellow.
Hi 5Riversz, that's a good question! The wiring on the pressure switch doesn't affect the switch. You can swap the wires and the switch will still function the same.
Very.good.videos..MR
Thank you Gabino!
When looking for the part online everything on the label matches except that at the end mine says D/C and the one I found says W/C does this matter?
Thanks for watching. There are a lot of part numbers and number systems so I'm not sure. D/C is often used to describe direct current. W/C is likely referring to the pressure in "water columns"
Do the other specifications line up? Can you match by any other ratings?
Hey soja good info. I have a good man furnace is it same like this one
Thanks for watching we're glad you found the video helpful! Yes the Goodman is a solid furnace overall!
@@AmreSupply my furnace is 8 year old u think it's time to change it. I had a guy came to look at it he say the flame sensor and the pressure switch is bad. He say I should get a new furnace. Can u advise me on this thank you
@@srla.5145 Most furnaces should last 15 - 20 years with some maintenance. The flame sensor can accessd and cleaned quite easily: ruclips.net/video/af_qRnfHFws/видео.html As well the pressure switch is simple to replace. Start with those parts before replacing the entire furnace. Two faulty parts is not indicative of a bad furnace. For example you wouldn't scrap a car just because the alternator failed, when it has a perfectly healthy engine.
Whats the white cap on the switch?
Hi Jamie, great question. The white cap on the switch port is just used just to differentiate one port from the other. Some have a white and red caps www.amresupply.com/part/12129054 and some switches use different color plastics in the switch body www.amresupply.com/part/12657129 Overall as long as you match the same port as before than you're in the clear.
Anyone know if a 'goodman' brans pressure switch will work in a 'lennox' furnace? They look very similar & amazon brought it up in the search. Any info would be helpful
Thanks for watching. Furnaces use switches and motors which often come from a variety of manufacturers. When finding a replacement there are often crossover parts. Just make sure to match the physical size and the rated specifications.
Does it matter which wire goes on which tab? I bought one with the same part # as the old one but the tabs are situated differently & both tabs are the same size so I'm concerned about connecting it backwards.
Thanks for watching. When it comes to these switches, they are not effected by polarity, they simply connect or disconnect power within a circuit. It doesn't matter which connector attaches to either of the 2 terminals, it will work either way.
I was looking for this question… thanks for asking…
Thanks for the answer… Vance
@@kenmiller2230 Glad it helped. Mine is working fine for its 2nd winter now & i like keeping the house REAL warm!
@@GenerallyGeneralLee
Just installed the pressure switch and the furnace.. 30 years old… working just fine…
so it doesn't matter which wire is connected to which terminal. What if my furnace has 2 switches? there is a "jumper" wire that goes from one switch to the other? I'm a little confused. thanks @@AmreSupply
thanks for the information, I have an older tridelta pressure switch with a purple wire and brown wire running to it in a Rheem 90+ updraft furnace, how to I tell which wire is common? and which is npc, thanks
Hi Cliff Harmon, always check your manual if you want to narrow down what each wire is but in this case reversing the wires will not affect the function of this switch. As long as you connect the same wires as before, than everything should work.
thanks, I did chase down the wires on the schematic but goes to a nine pin block and cant seem to find schematic for the 9 pine connector, howwever the purple wire is hot all the time so assume this is the hot, brown is COM
Hi Vance I have a Bryant 95s evolution. The furnace fan will not start but I can spin the fan motor manually and the fan goes and the heat comes on any ideas
Hi Stephen, thanks for watching. If manually spinning the fan causes it to work, then it likely has a failed capacitor. Capacitors are used with some motors and are needed to start the motor. This can be tested with a multimeter as shown here: ruclips.net/video/NkgxNLCrmr0/видео.html If the capacitor has failed, then replacing the capacitor will allow the fan to start normally.
@@AmreSupply thank you it also runs on fan only so maybe the capacitor isn’t involved when the is no call for heat?
@@stephendinger7114 Yes you are right that setting the thermostat to FAN will run the blower fan without igniting the burners (this setting is commonly used to just circulate air around the home between heating cycles) The inducer fan will only run when there is a call for heat so a faulty inducer capacitor won't affect things when you're just circulating air with the FAN setting.
Thanks very helpful.
We have an older furnace with a failing TriDelta Industries pressure switch. We had it diaged by a company but are not going to pay the astronomical fee to have them replace it. Replacing it looks straightforward enough, our only issue is, how do we find a replacement part for it when it's been discontinued? Our part number is FS4080-85. Any help would be greatly appreciated!
Thanks for watching. First look around for an exact match. Sometimes a part like that is still carried by some local HVAC shops but check online as well.
That part number doesn't show up in our system but if needed you can always use a universal pressure switch. You would simply need to match the terminals and set the universal switch to match the pressure rating. The pressure rating is in inches of water column and might show something like 0.5" WC. You'll want to match this exactly. As well make note of which terminals your original switch has and connect those on the new switch. The terminals are listed NO for normally open, NC for normally closed and COM for common. ruclips.net/video/yug_UfBUsec/видео.html
You can see a universal switch here; www.amresupply.com/part/9397688
Thank you so much! We were able to replace the switch ourselves for 86 dollars as opposed to 400!
@@nancyevergreen7530 You're welcome Nancy, we're happy to hear that the repair was a success!
My furnace randomly decides to turn on with a louder than normal inducer fan. Sounds like the inducer fan is starting in stage 2, instead of stage 1. When it does this, the furnace will turn off a few seconds after the hot surface igniter turns on, but just before the burners light. Would a faulty pressure switch cause this?
Hi Shawn, thank you for watching. A faulty pressure switch could cause this behavior. It can be helpful to check to see if your furnace is giving you any codes. These specific codes will be listed in the furnace manual or on a chart on the side of the door. The codes and the sequence of operation are both talked about here: ruclips.net/video/b0sAGt-1niU/видео.html
@@AmreSupply thanks for the reply. No codes are shown when this behavior happens, except for the normal a875 code. I ordered a new flame sensor and a pressure switch (hi/low). If this doesn't resolve it, what else could be causing this? Gas valve I guess?
@@Shawn855 Yes you are right that a faulty gas valve could create this problem as well. Definitely its smart to replace any small sensors or switches before replacing anything more extensive.
It shows you the plugging and unplugging, but no explanation of the meaning of the colors, I have brown, orange and yellow, where do they go?
Thank you for watching. The colors of the wires are often different in various models of furnaces. Best thing to do is to take a picture before disconnecting, and replace the same color on the same terminal it originated on.
Does it matter which wire goes to each terminal on the pressure switch ? I noticed one terminal says "com" the other says "on nc" I assume the "com" is the common or ground? and the other is where the hot wire goes?
Hi scientificfighting1, you are right that the "com" terminal is the common wire and that the hot wire should go to the "nc" terminal. The "nc" refers to "normally closed" which means that the switch is closed when the furnace is running, and the switch will open when the pressure is low.
Thanks for the fast reply. I got it all running now..looks like my furnace issue may now be solved. 😀
You're welcome! Glad you've got it up and running!
Hi scientificfighting1, just to clarify even though these switches may list "NC" and "COM" if you reverse the wires it will not affect the function of the pressure switch. As long as you connect the same wires as before, then everything should work.
Let me make sure I understand...if the same two wires that went to each switch are connected back to the same switch it doesn't matter which wire goes to which terminal as long as the same two wires are used ?
I have a 90% Goodman furnace.and its flashing 4 light's and that says open top air flow.how do i fix this problem.
Please help its cold here and i have kid's.
Hi Sanford, If its saying "open top airflow" and if you can verify that your pressure switch is tripping (furnace inducer fan runs but the furnace won't ignite) then check to see if there is adequate airflow in the heat exchanger, flue vent, and inducer and see if anything is blocking the airflow. If the airflow is good then the pressure switch could be faulty.
It seems simple to replace.....
Thanks for watching. Yes its more simple than some repairs that require you to take apart several things just to access the part.
But what if the pressure switch is not the problem?
Thanks for watching. It depends on how far into the sequence your furnace gets before stopping. This video covers all the different issues in the sequence: ruclips.net/video/b0sAGt-1niU/видео.html
Now if the Furnace stops before ignition, but the pressure switch is good, then it could be an issue with the airflow. This can be harder to narrow down and can be helpful to get it inspected by an HVAC technician.
To bad you don't show where yhe hoses coming out of the pressure switch go. My switch has negative and postive side outlets.
Thanks for watching. The inducer pushes the exhaust out of the system. Not all furnaces are configured the same but there will be negative pressure before the inducer fan and positive pressure after it.
ruclips.net/video/erpnfKbqmoM/видео.html
There's where those hoses go
Hola donde puedo encontrarlos en español
Translations into spanish aren't planned anytime soon. You can use the auto translate button on youtube.
Las traducciones al español no están planeadas pronto. Puede usar el botón de traducción automática en youtube.
My ignator only come on if I jump my wires bypassing my pressure switch is that mean my pressure switch is bad?
Hi Ramon. These pressure switches are meant to protect the furnace, so if you bypassed the switch and the sequence continues it either means the switch is bad.... or that the pressure inside the heat exchanger is too low for safe combustion. Just a note its not recommended to run the furnace continuously with anything bypassed.
If you replace the pressure switch and the ignitor still doesn't light, then that will prove that its a problem with the pressure. This can be caused by a blockage in the pressure switch tubing (causing the pressure switch to think the pressure isn't good) or a blockage in the inducer motor port or flue vent.
Hope this helps.
AMRE Supply thank you very much
You're welcome! Cheers.
If the igniter came on the pressure switch is good. Pressure switch contacts closing on slight vacuum is the step before ignitor being powered.
So a wasp nest was killing my furnace from running.
Thanks for watching! Wasps are officially the worst insect. We're glad you were able to narrow down the problem!
I ordered a new pressure switch by looking up the part #, but I didnt realize until I was getting ready to install it that the old part -0.35 PF and the new one is -0.30. How critical is this?
Thanks for watching. PF means pressure fall, and a lower rated switch will change how sensitive the switch is which can change how the furnace operates. We always recommend matching exactly but there are some cases where a certain range tolerance still works. Can't recommend for sure without seeing the system in it's entirety.
@@AmreSupply thank you. Is there any risk to trying it?
@@corey977 A different rated switch has the risk of the furnace shutting down within different parameters which is why we can't recommend using anything other than a match. As well depending on where you got the switch there are often no returns after installation, so once you install it, you're stuck with it.
you almost explained how the pressure switch works.
Thanks for watching. These were some of the earlier videos we made and we do go into a bit more detail in others. If you want to know how the pressure switch works we have a video on appliance components. I have liked the section on switches: ruclips.net/video/Mdu7QlAzWOg/видео.html
@@AmreSupply thanks. I was looking for more explanation on how the vacuum part works. where vacuum is and where pressure is. I knew my switch was good but the furnace would not turn on. I have been bypassing it for over a year, it is just a shop furnace and not used often. It is a single switch with 2 ports, one connected to the heat exchanger area and the other to the condensate trap. Turns out the hoses at the switch were swapped and giving the wrong signal to the switch. I did not find a diagnostic that would have caught this. And I don't have a in of water meter to measure the low pressure and vacuum being used. But this got my brain going and I was able to figure it out. I did learn how to tell how much the switch needed to trigger from your video.
I have a Trane XB Propane Furnace (2009) that will not light unless I tap on the air intake tube. I cleaned the flame sensor with steel wool. I've checked the pressure switch with your "soda straw" method, and I hear the 2 clicks. However, I suppose the switch could still be the problem. The inducer fan blows air, The ignitor glows, but the gas doesn't ignite. I don't have professional HVAC test tools, so I'm hoping I can fix this by simply replacing the pressure switch or ignitor. Here is a video I made of the issue: ruclips.net/video/QLoN2bT9MJE/видео.html
You shouldn't encourage people who don't know what they're doing to start digging around in their furnace. Not only could it be potentially very dangerous, but you are also selling the HVAC industry down the toilet.
Hi M.A. thank you for your feedback. There are countless DIY blogs, and videos on the internet explaining how to troubleshoot furnaces. Homeowners who are inclined to understand and troubleshoot their furnace will jump into it regardless and will research it on their own. We feel its important to provide solid information which also reinforces the overall safety. Given this there are still many people that will see a video, will see how it works, and will decide to call a professional. With a better understanding of the furnace this helps them communicate their problem to to a technician. Also any knowledge learned also protects the homeowner against any potential fraud as there are small number of non-reputable "professionals" who are quick to take advantage of someones lack of understanding of how a furnace works.
Its no different than car maintenance. Any consumer can buy parts for any model of car. There are some fixes that are simple and can be done in 30 min by anyone, but there are many repairs that are best done with the tools and knowledge that only professionals have.
As a homeowner, I have had the same issue on my furnace almost annually and I appreciate being able to get solid information so that I don't have to wait a week for a repair person, not only that, my furnace went out at 3 am in northern Minnesota at 38 below and if I wouldn't have found this information, I would've been in serious trouble. Thanks to these guys giving us ideas to temporarily remedy the issue I was able to blow into my pressure switch and my furnace started back up!
@@themythhunter9764 Thanks for sharing your experience! We have some extremely cold months in Canada and even a few hours without a furnace running can quickly add up so we understand your situation. We're glad this video helped you get your furnace running again!
When a "service" man charges over three times the cost of the switch and $175 for less than one-half hour of work...who is selling who?
I got a pressure switch for $59 dollars. You crooked guys wanted $199 just to show up and then $399 to change it. Screw you and your industry.