Furnace Blower (fan) stopped working

Discussion in 'HVAC' started by Wolf2000, Aug 5, 2010.

  1. Aug 5, 2010 #1

    Wolf2000

    Wolf2000

    Wolf2000

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    A few days ago, the furnace blower (fan) stopped working while my AC was on. Fortunately, my compressor didn't go bad.

    I opened the connections inside the t'stat to make sure they were fine - they were fine.

    I then opened the furnace back - realized there is a trip switch - tried turning it on - all I heard was a loud hum. The hum is really fairly loud (not loud enough to hurt the ears, but loud enough that you can hear it upstairs in the room above the t'stat).

    I figured it was the capacitor, so I ordered a new one. When the new one came in, I attached it. It WORKED... for a minute... then, the same thing, the fan stopped, and all I could hear was the hum.

    Please help if you can.

    thanks
    W
     
  2. Aug 5, 2010 #2

    kok328

    kok328

    kok328

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    Did you try to spin the blower by hand to check for any physical obstruction and/or binding of the bearings?
    Did you check to see what the voltage readings are going to the motor?
    Did you check to see what the current draw is from the motor?
    Otherwise, it appears that the motor itself would be the root cause of the problem.
     
  3. Aug 5, 2010 #3

    CraigFL

    CraigFL

    CraigFL

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    It's not uncommon for the motor to fail. It will then be hard to spin the fan. You can get replacement motors fairly easy. Find out the speed and voltage as well as the output shaft diameter-- they're pretty standard.

    Start here for info:

    Search furnace blower motor - Grainger Industrial Supply
     
  4. Aug 5, 2010 #4

    kok328

    kok328

    kok328

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    I've see more than a few motors smoke and still spin freely but, yea, sounds like this one bit the dust.
     

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