View Full Version : Blower on furnace turning off and on
taylorstout
May 23, 2007, 01:33 PM
The blower on the furnace (HEIL SP 80) keeps shutting off and on during the cycle it would be blowing. The normal cycle appears to be working but when the blower turns on it keeps shutting off and on. Does that make sense how I asked the question?
hvac1000
May 23, 2007, 01:41 PM
You need to check the motor when it shuts off. Turn off the power and feel the motor. Is it hot ?
taylorstout
May 23, 2007, 01:50 PM
The motor is hot but touchable.
hvac1000
May 23, 2007, 02:23 PM
Your blower control is probqably defective if the fan is not to hot. The board controls the fan. I am sure you already checked your filters?
Have you tried to set the blower on the thermostat to on instead of auto?
taylorstout
May 23, 2007, 02:47 PM
I took the filter off, everything looks clear. I even removed the front of the furnace and the fan blades are moving nice and smooth. I turned the fan to 'on' instead of 'auto' and it still shuts off and on.
hvacservicetech_07
May 23, 2007, 04:49 PM
Sounds like a bad relay on the control board, Does it do the same thing in heating?
taylorstout
May 24, 2007, 09:34 AM
I left the heater on for 10 minutes with the fan in the 'on' position. It has not shut off even 1 time?? (Now I'm turning the heat off!)
taylorstout
May 24, 2007, 10:27 AM
Thinking I was needing to replace the blower motor, I contacted a local company to get the part. After talking with her I realized what I thought was the motor was in fact the capacitor. It's the capacitor that's hot. When I push on it slightly I can feel the vibrations of it shutting off and on. I believe it's this part that's going bad. Would that make sense according to the description of my problems? This part is from Fasco Ind. And it had 2 numbers on it (if this helps to identify the part) No. 7021-8735 and P/N 1708-607. Thanks!