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-   -   Bad blower...? (http://www.houserepairtalk.com/f8/bad-blower-9491/)

Kevin5 06-30-2010 05:41 PM

Bad blower...?
 
I have a Trane XE60 that looks like it was installed in late 1989. I've owned the house for about 6-7 years now with no real issues to speak of, outside of a thermocoupler replacement. But about a week ago a metallic scraping/grinding sound started coming from the furnace blower. Eventually it would stop and operate normally. The frequency of the problem increased until now there is no air flow and all I hear is a low electric humming sound when I try to turn the air on.

I removed the furnace cover and tried to diagnose the problem myself (unsuccessfully). I did reach around and inside the shroud to see if the blower cage was wedge or scraping but it seems to move freely with no sounds. My guess is the motor itself is bad? or a bearing? Other internet research has pointed me to the capacitor that is mounted on the outside of the fan shroud - but would the symptoms I described result from a bad capacitor?

Any recommendations would be greatly appreciated. And given a cost estimate to fix/replace, would I be better off just getting an HVAC warranty, waiting 30 days and then just having them come take care of it?

Thanks in advance!

Wuzzat? 07-01-2010 11:46 AM

Quote:

Originally Posted by Kevin5 (Post 46191)
a metallic scraping/grinding sound started coming from the furnace blower.

The squirrel cage blower blade assembly may have a loose set screw so the blades are hitting something.

Kevin5 07-02-2010 07:58 AM

The blades turn/move freely though through several revolutions (without hitting anything) if I move them manually when the system is off. The problem right now is that when the system is on, all I hear is a humming sound with no blower assembly movement....

lloyd 07-11-2010 10:01 AM

If the motor is humming with no movement, I'd replace it. Take the cover off the furnace and see if the blower motor is hot.
You could try oiling it but I think you'd just be putting off the inevitable. I just replaced one yesterday that was doing the exact same thing (in a sweltering attic).

kok328 07-11-2010 04:53 PM

sounds like the bearings are shot and allowing the squirrel cage to drop and rub the housing. You may also have a fried motor now or possibly a bad capacitor that wont give the motor the required kick to begin spinning. If the motor shaft seems solid with no horizontal slop, try changing the capacitor as it's your cheapest guess.

Wuzzat? 07-12-2010 06:52 AM

Quote:

Originally Posted by kok328 (Post 46515)
try changing the capacitor as it's your cheapest guess.

And with a high likelihood of fixing it, so it's a win-win.


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