How to Repair a Freezer That's Constantly Running

If your freezer won’t stop running and you are wondering if it has been running for too long, there may be a problem with the thermostat, also known as the temperature control. The thermostat is a rotary dial with a capillary tube and bulb sensor attached to the interior liner of the freezer. The thermostat has internal electrical contacts which power the compressor circuit. These contacts are prone to welding or sticking closed. Check the thermostat for damage to the sensor bulb or the contacts, and replace the thermostat if you find any. Make sure to properly position the sensor bulb when replacing the temperature control.

If your frost-free freezer is constantly running, but is not cold enough, there may be an issue with the defrost timer. This type of freezer has a defrost heater to keep frost from building up on the evaporator coil. The defrost timer cycles the heater on when it is needed to defrost the evaporator. Failure of the timer can result in the compressor running continuously. To test the timer, manually advance it to prompt the defrost cycle. If the evaporator defrosts as usual, it means the timer is the problem and needs to be replaced.

If your frost-free freezer won’t stop running but doesn’t ever get cold enough, the defrost thermostat may be the source of the issue. The defrost heater circuit functions to keep the evaporator coil free of frost buildup. A properly functioning defrost thermostat allows the heater circuit to be powered in the defrost cycle. The defrost thermostat then signals the circuit to end the defrost cycle when the frost has been sufficiently melted. To test the defrost thermostat, use a multi-meter to check for continuity. The thermostat should exhibit continuity when at freezing temperatures, and switch to open circuit when the temperature is above 50 degrees Fahrenheit. If the defrost thermostat does not have continuity, it should be replaced.

If your freezer is constantly running, the user control, also known as the electronic display board could be the problem. This part is a feature on some freezer models, and is used to display, monitor, and adjust the temperature inside the freezer. If the control is not working, the compressor and fan motors may run continuously. Check the thermistor temperature sensor before concluding that the control is the part which needs to be replaced.

If your freezer runs all the time but never seems to get cold enough, it may mean there is an issue with the freezer defrost heater. Frost-free freezers have a defrost heater which keeps the evaporator coil free of frost buildup. The defrost timer prompts the heater to cycle on and melt the frost. If the heater is not working, the frost will build up and can cause other parts to malfunction. Check the defrost heater for continuity using a multi-meter, with the ideal result being less than 30 ohms.

If your freezer won’t stop running and the temperature is not being maintained correctly, it could be due to a fault door or lid gasket. The gasket creates a tight seal to preserve the cold air within the freezer. A gasket with cracks or leaks will lead to frost buildup on the evaporator, which causes the compressor to run continually. Check the gasket for any signs of damage. Areas where there is significant frost buildup can indicate where cracks or leaks are on the gasket. Replace a damaged gasket, and keep it in good condition by cleaning it frequently.