How to Troubleshoot a Payne Defrost Control Board

Shut off electrical power by unplugging the power cord. For larger appliances like commercial refrigerators, consider shutting off the circuit breaker to the power receptacle.

Examine the defrost control board for any obvious damage such as arcing or broken leads from the circuit board to related parts. Any visible physical damage can render the entire Payne defrost control board useless.

Disconnect the lead wires from the defrost control board to the thermostat. Turn on your multimeter to the resistance setting. Ensure the red and black leads are installed.

Touch the ends of the multimeter leads on the terminal ends of the thermostat, where the defrost control board leads were connected. If the meter readings move, the thermostat has resistance. If not, it needs to be replaced.

Apply power back to your unit. Reconnect the defrost control board’s leads to a working thermostat. Disconnect the lead for the outdoor fan motor and then turn on your unit’s heating mode so that frost begins to accumulate on the outdoor coil. Let this operate for 10 minutes.

Select the 30-minute defrost setting on the control board. Use a flatbed screwdriver to cause a short between the speed-up terminals on the defrost control board. If you don’t hear the reversing valve change position, the timer controls may be broken.