A faulty defrost thermostat can cause continuous refrigerator operation. The thermostat activates the defrost heater to periodically melt frost on the evaporator coils. If the thermostat cannot accurately sense coil temperature, the heater may not turn on for defrosting. This allows frost to accumulate, blocking airflow and cooling. The thermostat should be checked for continuity at low temperatures, indicating it is closing the circuit to trigger the heater. No continuity means the thermostat is not signaling defrost mode as needed. Replacing a defective thermostat restores proper automatic defrost functionality to prevent frost buildup so cooling can occur without the refrigerator running continuously.
The compressor circulates refrigerant to cool the refrigerator. If the fan motors and thermistor are working properly but the compressor runs continuously, the compressor itself may be inefficient. This is an uncommon issue. The fans and thermistor ruling out air flow and temperature reading faults point to potential compressor failure. An inefficient compressor has to operate excessively to attempt cooling. When other components are verified functional, the compressor should be inspected. Only an EPA certified technician can legally replace a faulty refrigerator compressor due to regulated refrigerants
The defrost heater melts frost off the evaporator coils periodically. A faulty defrost heater allows frost to continually build up on the coils. This makes the refrigerator work harder and run constantly to maintain cooling. Use a multimeter to check the defrost heater for electrical continuity. No continuity indicates a bad heater needing replacement. Proper operation will exhibit conductivity through the closed heater circuit. No continuity means the heater cannot heat to defrost the coils.
The thermistor senses refrigerator temperature and relays readings to the control board. The board controls compressor and evaporator fan operation based on thermistor input. With condenser and evaporator fans running, use a multimeter to test the thermistor. Resistance should vary with temperature changes. If resistance stays fixed, the thermistor could be providing faulty readings to the board, causing continuous running. The thermistor needs replacement if it cannot accurately detect temperature fluctuations.
A malfunctioning control board can lead to continuous refrigerator operation. Normally, the board initiates defrost mode periodically to melt frost on the evaporator coils. If the control board is defective, it may not cycle into defrost as needed. This allows frost accumulation which hinders proper cooling. The board not triggering defrost mode means frost remains on the coils, forcing the refrigerator to run constantly in an attempt to maintain temperatures.
A torn or faulty door gasket can cause constant refrigerator operation. Gaps allow warm humid room air to enter, forming frost on the evaporator coils. Normally the defrost cycle removes this but excess frost from a leaking gasket overwhelms defrosting. The refrigerator runs continuously trying to cool down as icy coils hinder proper temperature regulation. Gaskets should seal tightly when doors are shut to prevent air intrusion. Replace any torn or defective gaskets to restore an airtight seal.
A failed evaporator fan motor can cause continuous refrigerator operation. Evaporator coils cool air that the fan motor circulates throughout the compartments. If the fan motor fails, cold air will not flow properly. This prevents adequate cooling, making the refrigerator run excessively trying to reach temperature. Models with a single evaporator depend on the fan to deliver cold air from the freezer section to refrigerate the refrigerator compartment. If the fan motor stops, the freezer may still get cold but the refrigerator will not cool down since cold air can't reach it.
A faulty defrost control board can lead to continuous refrigerator operation if it fails to initiate defrost cycles. The board monitors conditions to determine when to activate defrosting. Without periodic defrosting, frost accumulates on the evaporator coil, reducing cooling efficiency and forcing the refrigerator to run excessively. The impact on temperature depends on the evaporator location. Before replacing the board, check the defrost heater and thermostat for continuity to confirm they are functioning.
A faulty defrost timer can result in constant refrigerator operation. The timer should activate the defrost heater to melt evaporator coil frost several times daily. If the timer is defective, it may not advance through the cycle to trigger the heater as needed. This allows frost buildup on the coils which reduces cooling efficiency, forcing the refrigerator to run excessively to maintain temperature. Replacing a defective defrost timer that fails to periodically turn on the heater can resolve the issue by restoring the automatic defrost function. This prevents frost accumulation through regular melting cycles so the evaporator can properly cool without requiring continuous compressor runtimes.
The damper control assembly is the component that regulates the flow of cold air from the freezer compartment to the refrigerator compartment in a side-by-side refrigerator. It consists of a plastic housing that encloses a mechanical flap or damper that can open and close to control air flow through the duct between the two compartments. If the damper control assembly is broken so that the damper flap fails to open properly, it will restrict cold air from moving from the freezer to the refrigerator. This makes the refrigerator compartment warmer than it should be. In response, the thermostat in the refrigerator compartment will signal the compressor to keep running constantly, trying to cool down the too-warm refrigerator section.
The evaporator cover is a plastic shield that protects the evaporator coils on the rear wall inside the freezer compartment of a refrigerator. The evaporator coils contain the refrigerant that absorbs heat from the freezer air as it circulates, creating the cooling effect. If the evaporator cover is damaged or missing, airflow can bypass the evaporator coils, preventing proper cooling. This leads to warmer temperatures in the freezer compartment. The thermostat senses this warmth and continues running the compressor to lower the temperature. However, since air is not being cooled properly by the evaporator, the compressor will run excessively trying to reach the set temperature.
A defective main control board can lead to continuous refrigerator operation. The board should cycle the cooling system off and activate the defrost heater periodically to melt frost accumulation on the freezer evaporator coils. If the control board is faulty, it may fail to initiate this defrost cycle as needed. The lack of defrosting allows frost buildup which decreases cooling efficiency, forcing the refrigerator to run excessively to maintain temperature. Replacing a malfunctioning main control board that does not properly cycle into defrost can restore the automatic defrosting functionality
Refrigerator door closing cams hold doors open and ensure full closure. Doors not sealing completely allow warm air intrusion, forcing continuous compressor operation to maintain cooling. Inspect the closing cam for damage causing inadequate closure. Cams should properly hold doors open while also enabling complete shut when swung closed. Damaged cams can prevent full closure, leaving gaps that compromise the seal and let warm air enter. This requires excessive cooling to offset the heat entering through openings.
The condenser fan motor circulates air over the condenser coils to cool the refrigerant, and issues with this fan can lead to continuous refrigerator operation. Debris caught in the fan blade or an inoperable fan motor can disrupt proper airflow over the coils. To inspect, pull the refrigerator out and remove the access panel to reach the condenser fan motor located underneath near the back. Check for obstructions in the fan blade impeding rotation. Test the motor for functionality. If the blade is blocked or the motor is defective, air will not properly flow over the condenser coils to cool the refrigerant, forcing the compressor to run excessively.
Condenser coils underneath the refrigerator dispel heat from the refrigerant flowing through them. Debris buildup on the coils blocks heat dissipation, forcing the refrigerator to work harder and run continuously to maintain cooling. Condenser coils should be cleaned twice yearly after first unplugging the unit. Use condenser coil brushes or bottle brushes along with vacuuming to remove dirt and debris from the coils. This allows proper air flow and heat transfer from the refrigerator to the coils.
For top, bottom, and side-by-side refrigerators with a single evaporator, the freezer temperature should be 0 to 5 degrees Fahrenheit. The refrigerator is cooled by air from the freezer. If the freezer is warmer than 10 degrees F, the refrigerator will take longer to cool, making the compressor run excessively. To prevent constant compressor operation, maintain recommended freezer temperatures below 10 degrees by clearing debris from condenser coils, ensuring the condenser fan runs properly, and checking for frost buildup on evaporator coils. Frost on the evaporator indicates a defrost system failure that can lead to insufficient cooling.
Ensure refrigerator doors are sealing completely when closed. If a door bin or food item obstructs closure, a small gap can remain open. This gap will prevent proper cooling, requiring the refrigerator to run continuously compensate. Doors that close completely allow efficient cooling without constant compressor operation. Obstructions keeping doors slightly ajar should be repositioned or removed so the doors can shut fully.
Optimal refrigerator operating temperatures range from 60 to 95 degrees Fahrenheit. Higher heat and humidity negatively impact efficiency, making the refrigerator work harder. When possible, maintain indoor temperatures within the 60 to 95 degree guidelines and keep the area around the refrigerator as cool and dry as feasible.