Goodman inducer bearing going bad

Old 02-12-20, 05:11 AM
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Goodman inducer bearing going bad

Got a very old Goodman GMP075-3 gas furnace that has developed a noisy inducer blower (been installed since 1997, at least).

I replaced the blower (FB-RFB859) Jan 2015...

This blower makes a weird warbling/squeaky noise on spin down--like a bearing going out. No noise during use or when it first comes on--only after a heating cycle, when power is cut and it starts to slow down.

The motor on the blower is fairly hot to the touch (170F on digital thermometer).

New blower ordered, but is this one safe to leave running another day or so (until replacement part arrives)? Do they normally get so hot?

I shut it off overnight, then ran the furnace a half hour this AM to warm the house a little. Would have run it longer but the main blower shut off with an upper limit switch error (4 blinks). Turns out the filter was dirtier than I anticipated (dog hair).

Now I wonder if the upper limit switch is related to a dirty filter or to the inducer blower... which didn't make any noise when fired up this morning.
Old 02-12-20, 05:57 AM
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The main blower should not shut off due to a high limit. I think the high limit may have been caused by the blower shutting off. After replacing the filter, try the furnace again. If you still get the high limit code, there's a pretty good chance the blower motor is an issue. How long since the furnace has been professionally cleaned & inspected? That model was known to have heat exchanger problems as well.
Old 02-12-20, 07:56 AM
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That furnace needs to be checked for a faulty heat exchanger. As said they were known to have issues.
If it’s cracked your furnace is dead and unusable.
This should be done prior to ordering or replacing any parts.
Old 02-12-20, 11:22 AM
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Not a limit switch keeping the main blower from working. It's buzzing when should be running. Can turn it by hand. No visible deformation of capacitor, but I'm crossing my fingers that's all it is. Don't know enough to test anything with meter.

Odd coincidence. I'm positive it was the inducer blower squealing when powered off (sometimes) and not main blower.

made a call for service.

I'll note everything else is working, no error light, the blower just won't come on/buzzes
Old 02-12-20, 12:46 PM
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Main air blower............
It may be the capacitor but more than likely it's a bad bearing requiring motor replacement.

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