Freezer Not Freezing? How to Fix the Cold Air and Defrost System
A freezer not freezing lets food thaw while the unit keeps running. Usually, the defrost system or a fan has failed and blocked the cold air. So check the evaporator fan and the defrost parts first. Below, we list the parts to inspect in order.
Parts to inspect for a freezer not freezing problem
1. Cold Control Or Temperature Control
The cold control is the thermostat that switches the compressor on and off to hold your set temperature. When it fails, the fridge may run nonstop or not cool at all. So turn the dial and listen for a click, then test it for continuity. Replace the control if it does not switch.
2. Evaporator Fan Motor
The evaporator fan blows cold air off the freezer coil and into the cabinet. When it fails, the freezer may stay cold while the fresh food side turns warm. Also, a worn motor often squeals or clicks. So test the motor and replace it if it is noisy or dead.
3. Electronic Control Board
The electronic control board is the brain that runs cooling, defrost, and the fans. When it fails, several functions can act up at once. Therefore, inspect the board for burnt spots or bad relays, and confirm it sends power to the parts it controls. Replace the board if it no longer responds.
4. Temperature Sensor Or Thermistor
The thermistor is a sensor that reports cabinet temperature to the control board. When it drifts, the board reads the wrong temperature and cools too much or too little. So test the thermistor’s resistance and compare it to the spec at a known temperature. Replace it if the reading is out of range.
5. Defrost Timer
The defrost timer switches the unit between cooling and defrost so frost does not build up on the coil. When it sticks, the coil ices over and airflow drops. So advance the timer by hand and listen for the mode change, then test it for continuity. Replace it if it does not advance.
6. Defrost Thermostat
The defrost thermostat closes at a cold temperature to allow the defrost heater to run. When it fails open, the coil never clears and ice blocks the airflow. Therefore, test the thermostat for continuity when it is cold. Replace it if it stays open.
7. Defrost Heater
The defrost heater melts frost off the evaporator coil during each defrost cycle. When it burns out, ice builds up and starves the cabinet of cold air. So inspect the element for breaks and test it for continuity. Replace the heater if it reads open.
8. Condenser Fan Motor
The condenser fan pulls air across the coils to shed heat from the system. When it slows or stops, the fridge cannot cool and the compressor runs hot. First, clear any dust or debris from the fan blade. Then test the motor, and replace it if it does not spin freely or run.
Get the parts
We supply OEM and replacement parts in bulk. Browse the Appliance Parts catalog, or request a bulk quote for volume orders.
Is the unit old or failing often? A new ENERGY STAR certified refrigerator can cut energy use, so weigh a repair against a replacement.
Most of the time, a freezer not freezing problem traces back to one worn part. So replace it, then run the unit and confirm the fix.