If your refrigerator is warm and not working but your freezer is cold, then something is wrong with one or more of the components in your refrigerator. In this article, we discuss the most common causes and how you can fix them.
Evaporator Coils Might Be Frosted Over
The first possible cause of a warm refrigerator is your evaporator coils being frosted over. This is caused by the defrost heater assembly becoming faulty, resulting in ice not melting off the coils, which adversely affects airflow.
To check the coils:
- Turn the refrigerator off at the power source.
- Locate the evaporator coils – you can find them at the back of the refrigerator unit (they look like a radiator). You may have to remove the back panel of the fridge to access them.
- Once located, inspect the coils for any signs of frost.
- If you find they are frosted over, then you’ll have to check each component of the defrost system.
Evaporator Fan Motor
The first component of the defrost system to check is the evaporator fan motor. This component acts to distribute cold air over the evaporator coils and then around the freezer. If the fan stops working, then your refrigerator will not be able to stay cold.
To check the fan:
- Make sure that the power to the refrigerator is turned off.
- Locate the evaporator fan motor – you can usually access it by removing the interior back panel in your refrigerator, or in some makes and models, you need to access it from behind the refrigerator.
- Once located, try turning the fan blade around manually. If it doesn’t turn around easily, then this indicates it is faulty and needs to be replaced. You should also replace the motor if the fan is very loud when it is operating.
- Finally, if the motor does not run at all, use a multimeter to test the motor windings for continuity. If the windings do not have continuity, replace the evaporator fan motor.
Damper Control Assembly
The next component to check is the damper control assembly, which is responsible for opening and closing to allow the correct amount of cold air into the refrigerator. When it fails to open correctly, your refrigerator will not be able to cool down.
To check it:
- Make sure the refrigerator is still turned off, and then locate the damper control assembly – if you have already taken the panels off to access the other defrost components, then you should be able to find it easily.
- Inspect the damper control to determine if it is broken or is unable to open and close properly. If you find it damaged, then it needs to be replaced.
Another possible cause of the problem is a faulty thermistor. This component monitors the temperature in the refrigerator and then sends it to the control board. The control board then knows how much power to send to the compressor and evaporator fan so your refrigerator can stay at a cool temperature. When it fails, then your refrigerator will be warm.
To inspect the thermistor, you need to:
- Make sure the refrigerator is still turned off.
- Locate the thermistor in your refrigerator.
- Use a multimeter to check the thermistor for continuity. If it doesn’t have continuity, then it will need to be replaced. The resistance in the thermistor should also change when the refrigerator temperature changes.
- If the thermistor is working correctly, you can move on to checking the defrost thermostat.
This component monitors the temperature of the evaporator coils, and when they drop below their desired temperature, the contacts on the thermostat close so that power can flow to the defrost heater when it is going through a defrost cycle. If the defrost thermostat becomes faulty, then the contacts don’t close and the fridge will ultimately not be able to operate correctly.
To check if the defrost thermostat is operating correctly, you need to:
- Make sure the refrigerator is still turned off.
- Locate the thermostat and then use the multimeter to check it for continuity when it reaches the lowest temperature in its range.
- If it has continuity, then it is working correctly, and if not, you’ll need to replace it.
If you’re still looking for the cause of the problem, the next component to check is the defrost timer. The main function of the defrost timer is to turn the defrost heater on every few hours to ensure frost on the evaporator coils gets melted off. When it stops working, frost might accumulate on the evaporator coils to the point that the refrigerator won’t be able to keep cool.
To check the defrost timer:
- Locate the defrost timer.
- Move the dial on it around to the defrost cycle setting.
- At this point, the compressor should shut off and the heater should turn on. If this doesn’t happen or if the defrost cycle doesn’t end after about 30 minutes, then this tells you the defrost timer is faulty and that it needs to be replaced.
Temperature Control Board
This component is responsible for providing voltage to the compressor and the fan motors. When it becomes faulty, it won’t send the required voltage, which means those other components won’t work. The temperature control board is difficult to test to see if it’s faulty; if you’ve checked out all of the other components and your refrigerator still doesn’t work, then replace the temperature control board and see if this solves the problem.
Main Control Board
If the temperature control board has been replaced and your refrigerator still won’t cool down, the final component to check is the main control board. If it has become defective, then this could be causing your refrigerator to stay warm even if your freezer is cold. It’s very difficult to test the control board to see if it is faulty, so if you have tried all of the other possible fixes above and it still won’t work, then consider replacing the main control board and seeing if that fixes the problem.