Troubleshoot of the gas furnace inducer

2 types of inducers are described. The 80% AFUE furnace and the 90% AFUE furnace inducers are shown. design and construction are covered. Symptoms of failures and reasons for failure along with replacement instructions are covered.
This video is part of the gas furnace series of training videos made to accompany my website: to pass on what I have learned in many years of service and repair. If you have suggestions or comments they are welcome.
If you are a homeowner looking to repair your own appliance, understand that the voltages and fuels used can be lethal and can cause a fire or explosion. Know your limits.

19 Replies to “Troubleshoot of the gas furnace inducer”

  1. I just replaced my 80% inducer with a Fasco OEM. It didn’t come with gasket and when I removed the old inducer the original gasket near the exhaust was so brittle it just crumbled. Couldn’t have been doing much over the past few years. I installed the new one without the exhaust gasket…do you see any issues coming? What can I use as a replacement?

    Also the inducer assembly housing, not the motor, seems to be getting very warm. Is that usual? I’m guessing it is but any information on that for piece of mind?

  2. An HVAC tech will try to charge you $2,000 to replace the inducer, pressure switches, flame sensor, and igniter. Watch these great vids and DIY all day folks.

  3. My inducer motor is leaking condensate on the seams of the black housing. Should inducer be replaced?

  4. Can the motor be disconnected from the fan to allow it to be replaced without replacing the entire unit?

  5. Thank you. This is the only logical explanation I have found so far to explain why these fail. Now I can shell out $150 every 10 years with less exasperation. Well done.

  6. I love watching this man explain systems….A no bullshit schooling and I always learn something….Thank you sir once again.

  7. I have an Older Dayton furnace with a bad inducer. The bad original inducer in the unit is a Fasco with an RPM of 3450. Many of the new inducer replacements for this old part have an RPM of 3350. Can I go with the new part with the lower RPM or will I have to find an older used duplicate with the same RPM? I was just wondering if the replacement part will generate enough CFM to trigger the pressure switches. Thank you for all of your great teaching efforts. Everything you do here is greatly appreciated.

  8. I was told what the inducer did and I was wondering why they keep running. I was under the impression that they only ran for a few moments.

  9. I got a blinking red light after it runs for about 5 minutes. The door panel says that it is a relay short . I checked the pressure switch, the eye probe , and small safety switches and everything seams to be working. I can't figure it out?

  10. thanks man, this helped me learn more about inducers.

    new apprentice so things are stressful when I don't know everything yet :/

  11. My plastic Fabsco has a Small dia plastic "Flow Reducer"(Flat plastic with smaller hole) Plastic-riveted to the center, apparently to redirect/focus air flow over the Heat Exchanger. This is the part that failed on mine and I'm sure it happens often, It is not protected from the heat because it is so flimsy and "added-on." It disintegrated and took out the fan wheel(Irreparable). Then, it is not sold with the Fabsco, you have to purchase it separately, from a separate supplier, and back-ordered. MY fan arrived first, and furnace was out in cold weather so I tried it. Cycle is wrong and furnace ineffective, so I assume it's essential. Why wouldn't they make it out of stainless or something? ANYONE have any other ideas, we're cold.

  12. Hi, I am Very thankful your posting and i wanna to ask that My furnace is working but the combustion air inducer seem like very very hot when the prowler is on. I am afraid that is abnormal or is fine? Do I need to change it?

  13. I have a Goodman furnace from the 90's or so I would guess since it has a shaded pole inducer motor. This week the igniter went out so I replaced that. Then a few days later the inducer motor wouldn't kick on at all. I checked the exhaust vent and pressure switch vacuum hose for blockages but everything was clean. Next I pulled the inducer motor itself and it also was clean as well as the port for the vacuum hose to the pressure switch. It also spun freely and the bearings all ran smoothly and with no play. I did notice that the gasket on the limitting plate had a lot of dry rot. So I put some high temp silicone on there to replace it thinking that the loss in pressure around the inducer housing may be just enough to not allow the pressure switch to function within range. I reinstalled it and it ran smoothly for a couple of days when it quit running again. This time when I powered the furnace on the inducer motor would flinch but not rotate all the way. Again this is a shaded pole motor and there is no capacitor for it. I checked the inducer motor for power and it was not getting any power. I checked for 24v from the thermostat to the control wire on the circuit board and that was good. It was about this time I noticed a small humming/buzzing noise coming from the control board which is still flashing the pressure switch failure code. Upon closer inspection the noise appeared to be a relay on the board very close to the power leg and common wire blade terminals feeding the inducer motor. I am ordering a new circuit board as this appears to be the issue that is preventing power from getting to the inducer motor. I probably could find the relay and replace it but I am not well practiced at desoldering and resoldering in small circuit board components also the circuit board is very corroded and is probably the original so there is no telling what may fail next. Circuit board component failure is definitely another cause of inducer motor failure. I didn't see this topic covered in the video but nonetheless your video(s) were very helpful in ruling out the other more common issues.

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