









Based on customer reports and repair data, this part commonly fixes these issues:
The wall thermostat has electrical contacts that send signal voltage back to the control board and the outside unit's contactor to run the heat pump system. If the contact that controls the contactor sticks closed, it will send continuous voltage to the contactor, causing the system to run continuously. To determine if the thermostat is defective, use a multimeter to test it for continuity. If the wall thermostat shows continuity between the red (“R”) and yellow (“Y”) thermostat wire terminals when the thermostat is in the “off” position, the thermostat has failed and will need to be replaced.