Symptoms
- Compressor hum never pauses
- Unit feels hot on the sides or back
- Higher than normal electric bill
- Freezer is colder than needed or has heavy frost
Likely causes
- CommonDoor not sealing fullyConstant warm air infiltration forces the compressor to run nonstop trying to keep up.
- CommonDirty condenser coilsDust-caked coils can't release heat efficiently, making the compressor work harder and longer.
- CommonFreezer placed too close to a wall or heat sourcePoor clearance traps heat around the unit and reduces cooling efficiency.
- PossibleThermostat set too cold or malfunctioningA stuck or miscalibrated thermostat can keep calling for cooling even at target temperature.
- Less commonLow refrigerant or failing compressorA sealed system leak or worn compressor struggles to reach temperature, running continuously.
What to do
- Check the door gasket and confirm the door seals fully using the paper test at multiple points.
- Unplug the unit and vacuum the condenser coils, usually located at the back or underneath.
- Ensure at least a couple of inches of clearance around the back and sides for airflow.
- Verify the thermostat setting is at the recommended level, not the coldest extreme.
- Check the room temperature around the unit; garages and sunrooms that get very hot make freezers run longer than normal.
- If the unit still runs nonstop after cleaning coils and confirming a good seal, have a technician check refrigerant charge and compressor function.
Tools and parts
- Vacuum with brush attachment
- Thermometer
Freezer door gasketSearch: “freezer door gasket seal”
When to call a pro
If cleaning coils and fixing the seal doesn't stop constant running, a technician should check refrigerant levels and the compressor.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.