If your refrigerator keeps running and won’t turn off when it should, then it could be one of many issues causing it. If you go through each of the possible causes below, you should be able to find the cause and then fix it.
Check the Condenser Coils
The first step is to check the condenser coils to see if they are dirty. When they get dirty, they must work harder than normal to remove heat, and this can cause the refrigerator to stay on constantly to help it cool down.
To check the coils to see if they are dirty:
- Switch the power off to the refrigerator, and pull it out from the wall.
- Locate the coils – you can find them under the refrigerator.
- Check the coils to see if they are dirty or frozen, and if so, give them a thorough cleaning. If they are not dirty, then move on to checking the next possible cause.
- Turn the refrigerator back on, and see if the problem has been solved.
One of the most common causes of a refrigerator constantly running is a faulty defrost timer. After the compressor in the refrigerator has run for 8 to 10 hours over a set period, the defrost timer will start a defrost cycle, which shuts the compressor down to essentially give it time to defrost. When the defrost timer becomes faulty, the compressor will not be able to operate correctly.
To check the defrost timer:
- Make sure that the refrigerator power is switched off.
- Locate the defrost timer. The location will depend on the specific make and model of the refrigerator, so check the manual. The most common locations are at the bottom of the fridge behind the kick plate, in the control panel, or at the back of the fridge.
- Once located, check if it is an electrical timer or a mechanical timer.
- If it is an electrical timer, then you need to check the timer for continuity by using a multimeter to test it. If it doesn’t have continuity, then it is faulty and will need to be replaced.
- If the timer is mechanical, then you can use a screwdriver to manually turn the timer around until you hear a click sound, and this should activate the heater switch. If it doesn’t activate the heater switch, then the timer is faulty and needs to be replaced.
If the defrost timer is not the cause of the problem, then the next component to check is the defrost heater. The defrost heater helps to defrost ice off the evaporator coils during the defrost cycle.
To check the defrost heater:
- Make sure the fridge is still unplugged.
- To get access to the defrost heater, you need to remove the evaporator cover at the rear of the freezer compartment.
- Locate the heater tube(s) and use the multimeter to test them for continuity.
- If they don’t have continuity, you need to replace them; if they do have continuity, then they are not the cause of the problem, and you can move on to checking the next possible cause.
Defrost Termination Thermostat
Another possible cause of the refrigerator not turning off is a malfunctioning defrost termination thermostat. This particular thermostat sends a signal to the defrost heater to turn off after a defrost cycle. When it becomes faulty, it won’t operate correctly, and your refrigerator will keep running.
To check if it’s faulty, you need to:
- Make sure that the refrigerator is still switched off.
- Locate the defrost termination thermostat – you will find it on the evaporator tubing.
- Use a multimeter to check it for continuity. If it has continuity, then it is working correctly, and you can check the next component. However, if it doesn’t show continuity, then it needs to be replaced.
Refrigerator and Freezer Door Gaskets
The refrigerator and freezer door gaskets are another possible reason your fridge won’t stop running. These gaskets help to make sure that your doors are closed properly and airtight. When they malfunction, your refrigerator may become too warm, which causes the refrigerator to keep running to lower the temperature.
To check if they are faulty, you can:
- Inspect the shelves in your freezer, around the edges of the doors, and the air outlet ducts for any signs of moisture. If there is moisture, then it’s a good sign the gaskets might need to be replaced.
- Check the gaskets for any signs of wear and tear and that they are still in their correct shapes.
- Check that your fridge and freezer are airtight by placing a thin piece of paper in the door and then closing it – you shouldn’t be able to easily pull the paper out if the gaskets are still working correctly.
- If any of the above tests fail, then replace the gaskets. Once replaced, turn your refrigerator back on and check if the problem has been solved.
Condenser Fan Motor
Some newer refrigerator models are frost-free and have a condenser coil that is cooled down with a fan. The purpose of the fan is to remove heat from the coils, and when the fan fails, your fridge won’t cool down enough, so it will keep running longer than it should.
To check the condenser fan motor, you need to:
- Make sure the refrigerator is unplugged.
- Remove the back access panel of your refrigerator, and locate the condenser motor fan – it will be close to the compressor.
- Attempt to manually move the fan around and check if anything is obstructing it, and if there is, remove the debris (you can use a vacuum cleaner to remove dust and other debris from the fan).
- Check for any signs of wear and tear on the motor, the fan blades, and the mounting grommets. If you find any damage, then that part will have to be replaced.
- Use a multimeter to check the fan motor terminals for continuity. If they have continuity, then they are working fine, but if they don’t, then the motor will have to be replaced.
Evaporator Fan Motor
The final possible cause to check is the evaporator fan motor. This fan motor helps the evaporator fan operate, and you can usually hear it operating from the freezer compartment.
To check it:
- Make sure that the refrigerator is still unplugged.
- Locate the evaporator fan at the back of your freezer compartment.
- Remove the panel that is covering the evaporator fan.
- Check if the fan is clogged up with ice, and if so, defrost the freezer.
- Check the fan for any signs of damage, and if you find any, like a broken fan blade, the fan will need to be replaced.
- Check the fan shaft to make sure the fan can turn around correctly – if it can’t, then you will have to replace the fan unit.
- Check the fan motor for continuity with a multimeter. If it has continuity, then it is still working correctly, but if not, it needs to be replaced.
- If you do replace the evaporator fan motor or any of its parts, you will then need to plug your refrigerator back in and test that the problem is now solved.