How to Repair a Freezer That's Frosting Up

If your frost-free freezer has frost buildup, particularly around the evaporator, there may be an issue with the defrost thermostat. This type of freezer has a defrost heater to melt frost from the evaporator coil to keep it from frosting over. The defrost thermostat supplies power to the heater, and signals the shut-off when the defrost cycle is complete. You can test the functionality of the defrost thermostat using a multi-meter; it should have continuity when at freezing temperatures, and should be open circuit when the temperature is above 37 degrees Fahrenheit. A lack of continuity means your thermostat will not power the heater, leading to frost in the freezer.

If your freezer is frosting over, it may be due to a broken door lid or gasket. The gasket creates an airtight seal between the door and freezer cabinet to keep the air inside cold. If the gasket is damaged, it may be letting warm, moist air inside the freezer, which can result in frost when it comes in contact with the freezing cold surfaces inside. If the gasket on your frost-free model has a leak, frost can build up on the evaporator, which means the compressor has to run more than usual. Check the gasket for leaks or damage. If the frost is specific to one area, that is likely where the gasket leak is. Replace the gasket if you find any cracks or damage.

If you are noticing frost in your freezer, it may mean there is an issue with the defrost timer. In frost-free freezer models, a defrost heater is used to melt frost before it can build up on the evaporator coil. The timer signals the heater to turn on at regular intervals for efficient operation. If the timer is not working, the heater will not run as usual and the compressor may run continuously. You can turn on the defrost timer manually to begin the defrost cycle; if the other components work normally, that means the timer is defective and needs to be replaced.