This is a control / relay board from the air conditioner for my RV. When the thermostat is set to off, the compressor of the AC starts humming. it seems like the control board is sending power to the compressor even when the thermostat is set to off. Also, changing the thermostat to furnace does not work. It seems like the control board is not responding to the thermostat. Both the AC and the furnace have been tested by a service center and they are fully functional. When I change the thermostat to cool, it does turn on the AC and works fine. Seems like the control board is working partially but not completely.
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