AC blower fan ramps up at night

Problems related to residential installations.

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AC blower fan ramps up at night

Post by auxarcman » Fri Jul 06, 2012 4:42 am

I have a new Heil heat pump with variable speed motor, and a new thermostat. During the day, with temps in the upper 90s, it seems to run great and cycle appropriately. At night, though, the blower motor ramps up really high (loud) and runs continuously. Tech came yesterday and said the coolant was low, which was probably the problem, so he charged it up. However, it's the middle of the night now and the blower is running full-out, even though the set-temp has been reached. Anyone have any ideas as to why, when the temp is lower outside, the blower runs so hard?

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- AC blower fan ramps up at night

Post by Freon » Fri Jul 06, 2012 2:12 pm

How old is the system? Has this problem recently developed? Have you had any work done on the system... new thermostat or annual maintenance servicing? Any recent electrical storms before this behavior started?

It could be a control board issue or a thermostat issue. I would remove power to the entire system for 20 minutes and then restart. Maybe a reset of the control circuit is all you need. Let us know what happens.

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