This DIY repair guide explains how to replace the defrost thermostat in an upright freezer. The defrost thermostat, also called a bi-metal, protects the evaporator by turning the defrost heater off if the heater gets too hot. If the defrost thermostat stops working, frost forms on the evaporator fins, and the temperature in the freezer rises. Replace the defrost thermostat with the manufacturer-approved freestanding freezer part if it's no longer working.
Use these basic steps to replace the defrost thermostat in Kenmore, Frigidaire, Electrolux, GE, Whirlpool, Gibson, Crosley, KitchenAid, Tappan and Amana freezers.