FASCO Furnace Inducer Fan Noise

[DLausche]

Do we have any HVAC experts out there? I have an 11 yr old Trane XE80 furnace. It is a cheapo furnace that came with the house and up until this year has worked just fine. A few weeks ago the inducer fan started to make a really loud squealing noise. Bearings were dry and makin noise. I found a good deal on a new FASCO A143 inducer blower unit. It was a snap to replace it. Only problem now is I can hear the hum from the motor all through the house. The vibration travels through the chimney pipe which is of course fastened to the house and thus the noise is heard through a good part of my home. It is not terribly noisy but it is a lot more noticeable than the old blower motor. Question for you guys is there anything I can do to reduce the motor/fan noise? It does not appear to be vibrating or anything bad like that. It is like a humming noise that goes thru the house. I tried taking off a very small factory balance weight from one of the fins (marked so I can put it back in same spot if needed) but that did not make any difference. Should I put the squirrel cage from the old blower onto the new motor. This would be easy to do except I will need to replace the fiberglass gasket if I R&R the blower unit again and I do not have one on hand. The old blower was nice and quiet except of course recently when the bearings went out. I've also tried shifting & loosening the vent pipe and connections to no avail. I suppose I could also try to find bearings for the old unit but not sure where I might find the right size bearings.



-Deon

 

[daytripper63]

Do we have any HVAC experts out there? I have an 11 yr old Trane XE80 furnace. It is a cheapo furnace that came with the house and up until this year has worked just fine. A few weeks ago the inducer fan started to make a really loud squealing noise. Bearings were dry and makin noise. I found a good deal on a new FASCO A143 inducer blower unit. It was a snap to replace it. Only problem now is I can hear the hum from the motor all through the house. The vibration travels through the chimney pipe which is of course fastened to the house and thus the noise is heard through a good part of my home. It is not terribly noisy but it is a lot more noticeable than the old blower motor. Question for you guys is there anything I can do to reduce the motor/fan noise? It does not appear to be vibrating or anything bad like that. It is like a humming noise that goes thru the house. I tried taking off a very small factory balance weight from one of the fins (marked so I can put it back in same spot if needed) but that did not make any difference. Should I put the squirrel cage from the old blower onto the new motor. This would be easy to do except I will need to replace the fiberglass gasket if I R&R the blower unit again and I do not have one on hand. The old blower was nice and quiet except of course recently when the bearings went out. I've also tried shifting & loosening the vent pipe and connections to no avail. I suppose I could also try to find bearings for the old unit but not sure where I might find the right size bearings.



-Deon

I am a heat / air contractor and sometimes you will just get a noisy motor but it is rare, what I would do is loosen all the inducer housing mounting screws at where they secure to the furnace and snug back up evenly do not over tighten and then where the motor bolts to the inducer housing loosen then gently snug back up, the motor to housing bolts need not be to tight. If it is still noisy I would exchange it for a new one, but be sure to check the motor to housing bolts first, they shouldnt be too tight

Robert

 

[daytripper63]

When checking the motor to housing tightness I believe the A143 is the model with the aluminum spacer and a motor cooling fan between the motor and the inducer housing so be sure to check the motor to alum spacer tightness and alum spacer to inducer housing tightness

Robert

 

[TowPro]

Still got the old one? Rebuilt it, put it back into service and keep the noisy one as a spare.

 

[daytripper63]

Still got the old one? Rebuilt it, put it back into service and keep the noisy one as a spare.

These things are to cheap to rebuid, the motor is a little 3 3/8 diameter pinch together body.

If he needs another one i can sell it to him at wholesale

 

[DLausche]

When checking the motor to housing tightness I believe the A143 is the model with the aluminum spacer and a motor cooling fan between the motor and the inducer housing so be sure to check the motor to alum spacer tightness and alum spacer to inducer housing tightness

Robert

Thanks for the tips. I checked all of the fasteners and loosened them and just snugged them up a bit. Yes, you are right, the A143 has an aluminum spacer with fan between the motor and the inducer housing. There are 3 nuts holding the motor/Al spacer to the inducer housing and on each there is a rubber isolator. I loosened these up and tightened so the rubber isolator was just starting to compress - just barely enough so the nuts won't come off by themselves. The aluminum spacer looks to be permanently fastened to the motor but to check for sure I would have to disassemble the whole blower assembly to see in there. I think it is as quiet as this one will get. I'm not sure what is reasonable for me to expect as far as sound level. Wife says she can live with it, but I can hear it upstairs and the old one was not like this at all. If I hold my hand on the motor when it is running I can feel it vibrate. Not a lot, but I can feel it and this is obviously what is causing the noise.



I am leaning towards asking the place I ordered it from if they will exchange it. I just don't think the noise should be this noticeable.



-Deon

 

[DLausche]

Still got the old one? Rebuilt it, put it back into service and keep the noisy one as a spare.

Ya, that was my thought too. I tried tonight to see if swapping the squirrel cage from the old unit onto the new motor might fix the noise issue. My thought was that the old blower apparently was well balanced cause it made no noise at all. Well, these things are made really cheaply. It would not come apart and just a little bit of tapping on the shaft resulted in them motor being all screwed up and out of whack.



-Deon