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my furnace motor makes a buzzing noice before blower starts, is the motor about to **** out on me?

I have a thermal zone furnace #GU100M16B. The motor (part #902128) makes a buzzing type sound before the blower starts. Is this an indication the motor will be going out soon? There's also a run capacitor mounted on the side of the blower housing, can the sound have anything to do with it?
Please advise


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2 Answers from these members:
Joseph Perez
During this time of year it is very important to have the furnace working properly and not making any strange noises. While you are waiting for an expert answer, I did manage to find a link that describes a similar problem to the one that you are having. I am also including a second link in where you can enter your model number and your owners manual will pop up so that you can look in the trouble shooting pages. I hope my links are useful.
by Joseph Perez Earned 1,602 community points in Building Supplies
December 29th, 2010
Answered in 2 hours
0 votes
scott d
I can understand your concern. If the noise is actually coming from the motor, it could be a weak motor and could be a sign it’s going out. A good check will be to spin the blower wheel and see if it starts to run. This would indicate a weak capacitor. You must be very careful spinning the blower, so your fingers do not get caught. Another check would be to see if, there is voltage to the motor, when you hear this noise. Be very careful making this voltage check. There should not be any voltage to the motor until it starts. If there is voltage (120 volts) and the motor is not running, then it will be a defective motor. If there is no voltage there while you hear the noise, I suspect the vent (inducer) motor is the source of the noise. It will come on before the blower starts. This would be normal. I hope this helps you. Thank you for using Manage My Life.

If you do not feel confident repairing this problem yourself, then you can have it repaired at your home by a Sears technician. Here is a link for the website:

Sears Home Services


Safety Notice

: Be sure to disconnect the appliance before performing any troubleshooting procedures. If you are not comfortable with doing any voltage checks or repairs that might be recommended, please contact a local service provider for repairs. Be aware that there could be sharp edges inside the appliance that could cause cuts or other injuries to yourself or others.
by scott d Earned 3,459 community points in Building Supplies
December 30th, 2010
0 votes
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