Customer Questions and Answers for Refrigerator Defrost Control Board by Whirlpool

Robert, the unit can be placed into a forced defrost mode by turning the thermostat to the off position for 15 seconds, turn it back on for 5 seconds. This will be repeated two more times and then the thermostat moved back to the off position. The defrost control 4388931 will then enter into a forced defrost cycle for 21 minutes or until the defrost bi-metal W11164040 opens.