My Kenmore Refrigerator's Freezer Is Not Defrosting

Defrost Timer

• One of the most common problems with a self-defrost system is the defrost timer. This part of the system is responsible for signaling the compressor to shut down and the defrost heater to turn on. It keeps up with how long the defrost cycle lasts and returns the system to normal cooling when enough time has elapsed to clear the evaporator coil of frost. If the timer gets stuck in the cooling cycle it will not defrost the freezer at all, while being stuck in the defrost position will cause the refrigerator not to cool. Replacing the part is the simple solution to the issue. The timer is typically inside the refrigerator near the temperature control dial or behind the kick plate on the backside of the unit.

Defrost Heater

• The defrost heater is the component of the self-defrost system that does the work of removing frost from the evaporator coil. When the timer tells it to turn on, the coils in the heater warm up and melt away the frost. The timer will tell it to shut off within a few minutes until it is needed again. If the heater is in disrepair it may not heat at all and will prevent the refrigerator from defrosting. You will be able to hear the condensation dripping onto the heater during a defrost cycle because the hot surface and the cold water will create a hissing or a popping sound. If you can’t hear this and there seems to be no defrosting, the heater may need to be replaced if the timer seems to be working.

Bi-Metal Switch

• The bi-metal switch, also known as the defrost thermostat, lets the self-defrost system know when the temperature drops to a certain level in the freezer. This is one way the system knows to begin defrosting. Not all Kenmore refrigerators have this component as some may rely solely on a timer. But some models do have a bi-metal switch, and if it is not indicating the proper temperatures, the entire system may fail to come on when needed. Replacing a bad bi-metal switch may be in order.

Consequences

• Unless you want to deal with manually defrosting your refrigerator regularly and having to find alternative storage for perishable foods, you should have the defrost system repaired. Failure to take care of this problem may lead to more difficult issues such as restricted airflow when ice buildup inside the freezer chokes off the flow of cold air throughout the refrigerator. This will affect cooling and could put your food items at risk of spoilage.