Heater not blowing on low settings

wrapp

Member
Joined
Sep 22, 2020
Messages
40
Location
Indianapolis, IN
My HVAC mysteriously stopped blowing when on the lower two settings. It works perfectly fine on the higher two, but nothing comes out any of the vents on the lower two settings. Any idea what could be going on?
 
The resistor is a cinch to replace. ...I've done it twice.

It's bad again. Am I just getting cheap resistors or is there something that might be making mine go bad after about six months?
 
The blower fan is probably either full of leaves and crap or failing. Sometimes the wiring goes bad but the motor is what I'd try first.
I've always replaced both the resistor and motor as a pair. Usually when one goes bad the other isn't far behind.
 
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The resistor is a cinch to replace. ...I've done it twice.

It's bad again. Am I just getting cheap resistors or is there something that might be making mine go bad after about six months?
Your fan motor is bad, its windings are starting to short out from the shellac insulation breaking down. When that happens it starts drawing excessive current which burns up the resistors in the resistor pack. Replace it and check the wiring between the switch and resistor pack for signs of overheating.
 
Resistors repeatedly going out are likely caused by the motor going out and drawing excessive current due to shorted windings. See post #11 above.
May be so but, if you read carefully you will see I GOT 10 YEARS out of just replacing JUST the resister so obviously you do not always need to replace one motor per resister was my only point.