The part(s) or condition(s) listed below for the symptom Freezer runs all the time are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
The temperature control thermostat directs voltage to the compressor, evaporator fan motor, and condenser fan motor. If the temperature control thermostat is not working properly, it can cause the freezer to run continuously. To determine if the thermostat is defective, rotate the thermostat from the lowest setting to the highest setting and listen for a “click.” If you hear a click, the thermostat is not likely defective. If you do not hear a click, use a multimeter to test the thermostat for continuity. If the contacts inside the thermostat do not open, even at the lowest settings, this indicates that the thermostat is defective. If the temperature control thermostat is defective, replace it.
The evaporator fan motor draws air over the evaporator coils and circulates it throughout the freezer. On most refrigerators, the fan motor will not run when the door is open. Make sure that the refrigerator door is closed and the door switch is activated. If the door switch is activated but the evaporator fan motor still won’t run, replace the evaporator fan motor.
The defrost timer turns on the defrost heater several times throughout the day to melt any frost that may have accumulated on the freezer evaporator coils. If the defrost heater does not turn on, frost will continue to accumulate on the evaporator coils, and the coils will eventually frost over. In order for the defrost timer to turn on the defrost heater, the defrost timer must advance into the defrost cycle. If the defrost timer is not advancing properly, the defrost heater won’t turn on. To determine if the timer is defective, slowly turn the timer with a screwdriver or by hand. Turn the timer until it clicks. When the timer clicks, the compressor and fans will shut off. If the defrost thermostat and heater are working properly, the heater will turn on. If the heater turns on, this indicates that the timer is defective and must be replaced.
The defrost heater turns on several times throughout the day to melt away any frost that may have accumulated on the freezer evaporator coils. If the defrost heater assembly has burned out, the evaporator coils will frost over. If the evaporator coils are frosted over, air won’t be able to pass through the coils and cool the freezer. To compensate for the decrease in cooling capacity, the freezer will run continuously in an attempt to keep the freezer cold. If you suspect that the defrost heater isn’t working, first check the evaporator coils. If the coils are plugged with frost, the defrost system is not working properly. Next, use a multimeter to test the defrost heater for continuity. If the defrost heater does not have continuity, replace it.
The defrost heater turns on several times throughout the day to melt away any frost that may have accumulated on the freezer evaporator coils. Before the defrost heater turns on, the defrost thermostat must sense that the evaporator coils are cold enough. If the coils are cold enough, the defrost thermostat will allow the defrost heater to turn on. (Usually, the temperature of the coils must be below 30 degrees Fahrenheit.) If the thermostat is defective, the defrost heater won’t turn on, causing the evaporator coils to frost over. To determine if the defrost thermostat is at fault, use a multimeter to test the thermostat for continuity. If the defrost thermostat does not have continuity, replace it.
If the condenser coils are located within the freezer walls, the coils do not require cleaning. However, if the condenser coils can be readily accessed from behind or under the unit, you should clean them every 6-12 months. If the condenser coils are dirty, they won’t be able to dissipate heat effectively, greatly reducing the cooling capacity of the freezer. If the condenser coils are dirty or have not been cleaned in a while, clean them.
If the freezer only freezes the top shelf, there may be a sealed system leak in one of the shelves. Sealed system repairs are usually cost-prohibitive. If the sealed system is leaking, you will probably need to replace the freezer.