Home Furnace Noise?


Jun 11, 2001
I replaced the filter for my home furnace and shortly after, about two days, it started to squeal occasionally, like a worn belt on a car. I am not sure what I am looking at or looking for. Can anyone point me in the right direction to try and cure this?


Well if the Cage is driven by a belt then ,,you need a new belt.
IF it is a direct drive see if the motor has small caps at each end ,to add drops of oil..
Maybe the door is not on all the way,,can get a whistling noise from that ...
Thanks so much. It is in such a small space I have a hard time seeing it:( I did not see a belt and will try to find caps so I can lube it up. What should I use?
the squealing could also be the squirrel-cage shaft bearings.

Also, just check the furnace housing itself, both mine and my parents furnace gets a 'squeal' sometimes, and it's just the burner door & housing squeaking...
Thanks guys. There is so little room to see or do anything with it! I don't think it is the door, but I will try something with it. I am off to the hardware store to get some zoom.
Most of the time on newer furnaces the fan is direct drive off the motor, meaning the blower wheel is mounted right to the motor shaft. The advice above is good IF its belt driven and IF its got oil ports. DO NOT oil it if it does not have the removable plugs Dennis mentioned. It can hurt the motor. If it is direct drive, its likely a bad motor. I run a HVAC company, and we charge roughly $300 to replace motors, depending on size and such. Its not hard, but finding a replacement motor may be, as most supply houses won't sell to the public. Try a "farm" supply store. They have some stuff like that. If you need further help you can call my business at 217-398-5977, ask for Sam.
*If* it is belt driven,don't forget to oil the bushings for the cross shaft that supports the blower cage.
That can make the belt squeal.
Should receive a few drops every 6 months or so.
Thanks for all the help.
I spoke with Sam, who was very helpful.
It is a direct drive motor that is probably bad.

Get the horse power and frame numbers off of the motor and call WW Grainger, they carry the dayton brand of motors and can save you some money. I did that with my Moms furnace.
Tarey D.
Originally posted by camino70
Thanks for all the help.
I spoke with Sam, who was very helpful.
It is a direct drive motor that is probably bad.

If you can work on your car then you can do this simple fix,now that you spoke to Sam and know the problem,,,

did you hold the phone up to the furnace..:D :D
I took the doors off of it to poke around again and when I was finished looking, I gave them a nice smack with a rubber mallet to get them back into place and haven't heard the squeal yet... so maybe it was the darn doors... I guess we will see here in a day or two.

The furnace is getting pretty old so who knows. Maybe the noise was just in my head.