Customer Questions and Answers for Defrost Timer (Refrigerator) by Whirlpool

The defrost timer controls your refrigerator's automatic defrost cycle, periodically pausing cooling to power the defrost heater. Replacing a faulty timer restores proper defrosting to help prevent frost buildup, temperature swings, and excessive run time.

• Advances the system between cooling and defrost at set intervals
• Sends power to the defrost heater, then returns the unit to cooling
• Failure may cause heavy frost on evaporator coils and weak airflow
• Fresh food section may run warm while the freezer ices over
• Unit may run constantly, never defrost, or get stuck in defrost

• Disconnect power before servicing
• Location varies by model; access the timer (often in the control housing or rear compartment), note wire positions, and transfer one at a time
• Mount and secure the timer as originally installed; reuse existing bracket/fasteners
• After reassembly, restore power and verify the unit advances through cooling and defrost