Furnace blower vibrating


Old 04-10-14, 12:53 PM
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Furnace blower vibrating

What can I do about the blower vibration? It's a squirrel cage. Makes vibrating sound while running, when it's slowing down its a noticeable thud sound in a specific pattern. When you press in on the squirrel cage or try to wiggle it, it makes the same thud noise as if it has too much play in it.

So from my little bit of messing with it, I'm 100% sure that the noise is coming from the motor. I removed and replaced the three motor mounting bolts, so they're fine. It still made the sound with the motor assembly detached from the mounts. Is the motor worn out? The unit is only about 3 years old.
Old 04-10-14, 03:10 PM
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Sounds like a bad or missing bearing. Maybe a loose belt.
Old 04-11-14, 07:36 PM
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look for a sticker, paper or insulation in the squirrel cage first. Slowly rotate the cage around, is it wobbling in an out of round pattern? Is the hold down screw secured tightly on the flat? If it has a center disc, is it loose?
To check the motor, grab the shaft and check it for hand shaking movement. In and out is ok ( for about 1/8 inch) but there should be absolutely no side to side play. If it does, replace the motor and cage. If the motor failed, its likely due to a bad cage.

Last edited by hvac01453; 04-11-14 at 07:37 PM. Reason: additional info

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