Customer Questions and Answers for Defrost Heater (Evaporator) by Whirlpool

This evaporator defrost heater melts frost from the freezer's evaporator coil during the automatic defrost cycle, restoring proper airflow and cooling. Replacing a failed heater helps prevent recurring ice buildup and temperature swings.

• Heats the evaporator coil at set intervals to clear ice
• Maintains airflow so the fresh food section and freezer cool consistently
• Common signs of failure: heavy frost on the back freezer panel or evaporator
• Other symptoms may include warm refrigerator temperatures, reduced airflow, or fan noise from ice contact

• Disconnect power before servicing; wear appropriate PPE
• Access the heater behind the freezer's rear panel; defrost ice with warm air/steam—avoid sharp tools
• Reinstall in the original position; keep wiring clear of the fan and moving/hot parts; ensure secure harness connections
• After reassembly, verify the defrost cycle per service instructions; if frost returns, also check the defrost thermostat/bi-metal and control