This Refrigerator Defrost Thermostat is a safety device that clips onto the evaporator in the freezer. The thermostat turns off the defrost heater in case it gets too warm in the freezer section. If your refrigerator does not defrost, replacing the thermostat may alleviate this issue. To access the part, open the freezer door and remove the shelves, mounting brackets (if they release), and the ice bucket. After you remove the back panel, the defrost thermostat is mounted to the end of the evaporator. Replacing the element will require basic hand tools, some disassembly of the refrigerator and novice repair experience. You must unplug the appliance or shut off the house circuit breaker for the appliance before installing this part.