9 Reasons Your Mini-Fridge Is Not Cooling

If your mini-fridge isn’t cooling, it’s almost certainly due to one of 9 potential reasons. In this guide, we will take you through each of those reasons and then give you step-by-step instructions for how to solve them so you can get your mini-fridge cooling again.

Simply start from the top of the guide and work your way down until you find which one of the reasons is responsible for your mini-fridge not cooling.

1. The condenser coils might be dirty

One possible reason why your mini-fridge is not cooling is if the condenser coils at the back of your fridge are dirty. When they get covered in dust, they have to work overtime to try and keep your mini-fridge cool, and sometimes this won’t be enough, and your fridge won’t be able to cool down to a low enough temperature.

Cleaning the coils is simple, you just need to:

1. Turn the power off to your mini-fridge and pull it out from the wall.
2. Locate the condenser coils. If they are covered in frost, let them defrost and then give them a good clean. If they are covered in dust, give them a good clean with a damp cloth.
3. Once clean, turn your fridge back on and monitor it over the next few hours to see if this has solved the problem. If your mini-fridge still doesn’t cool, you can proceed to the next possible reason.

2. The condenser fan might be defective

The next reason to investigate is a defective condenser fan. The condenser fan blows warm air over the condenser coils to prevent them from frosting over. If the fan stops working, the coils won’t stay cool, and your fridge might not be able to cool down to a low enough temperature.

The condenser fan can be checked by following these steps:

1. Unplug your mini-fridge.
2. Locate the condenser fan and take the cover off it. You can then try and move the fan around manually. If anything is obstructing the fan, remove it. If the fan can move around without obstruction, check the fan motor with a multimeter.
3. If the test shows the motor has continuity, move on to checking the next possible reason. If the fan doesn’t have continuity, the condenser fan will need to be replaced.
4. Once the new fan unit is installed, check if your mini-fridge now cools. If not, move on to checking the next possible reason.

3. The evaporator fan might be faulty

Depending on the specific make and model of your mini-fridge, it might have an evaporator fan. This fan helps to transfer cold air from the small freezer compartment in your mini-fridge into the main fridge area. If it stops working, your mini-fridge might struggle to cool.

The evaporator fan can be checked by following these steps:

1. Open the freezer compartment door and check if you can hear the fan operating. If it’s not making any loud noises, then it’s probably fine, so you can move on straight away to the next possible reason.
2. If the fan isn’t operating, turn your fridge off and remove the cover from the evaporator fan.
3. Next, try to move the fan around to see if anything is obstructing it. If obstructed, remove the obstruction, and then check if the fridge works.
4. If nothing is obstructing the fan, test the fan motor with a multimeter.
5. If the motor has continuity, it’s working properly, and you can move on to checking the next component. If it doesn’t have continuity, replace the evaporator fan unit.
6. Once the new fan unit is installed, check if your mini-fridge now cools. If not, move on to checking the next possible reason.

4. The compressor might be faulty

The most important component within your mini-fridge is the compressor. The compressor produces refrigerant that is then pumped around your fridge to ensure it stays cool. If your mini-fridge doesn’t cool, the compressor is the one of the first components you need to rule out as the cause of the problem.

Here’s how to inspect the compressor:

1.   Turn the power off to your mini-fridge.
2.   Locate the compressor—it’s at the back of the fridge.
3.   Use a multimeter to test the compressor. You can do the test by placing the probes onto the pins on the side of the compressor.
4.   If the multimeter test shows an open circuit, the compressor will need to be replaced. This repair will need to be done by a qualified technician as it requires specialist knowledge and tools. However, given the cost of replacing the compressor, you might be better off buying a new mini-fridge. If the compressor doesn’t have an open circuit, it’s working fine, and you can proceed to the next possible reason your mini-fridge doesn’t cool.

5. The start relay might be defective

The start relay works in conjunction with the start winding to help the compressor operate. If it becomes defective, your mini-fridge will struggle to stay cool.

The start relay can be checked by following these steps:

1. Unplug your mini-fridge.
2. Locate the start relay (you’ll find it connected to the compressor unit).
3. Test the start relay with your multimeter.
4. If the start relay doesn’t have continuity, it will need to be replaced. On the other hand, if it does have continuity, it’s working fine and you can move on to check the next possible reason.
5. If you do replace the start relay, you’ll need to test if it has solved the cooling problem once it’s installed. If your mini-fridge still doesn’t cool, check out the next possible reason.

6. The temperature control thermostat might be faulty

The temperature control thermostat monitors the temperature in your mini-fridge and then directs voltage to the evaporator fan motor, the compressor, and the condenser fan motor as needed. If it stops working, your whole fridge will stop cooling.

The temperature control thermostat can be checked by following these steps:

1. Unplug your mini-fridge.
2. Locate the temperature control thermostat.
3. Move the thermostat from the lowest setting to the highest setting. When you move it to the highest setting, you should be able to hear a clicking sound. If you hear the clicking sound, the thermostat is working and you can move on to checking the next possible reason. If you don’t hear a clicking sound, test the thermostat with your multimeter.
4. If the thermostat doesn’t have continuity, it will need to be replaced. On the other hand, if it does have continuity, it’s working fine, and you can move on to check the next possible reason.
5. If you do replace the thermostat, you’ll need to test if it has solved the cooling problem once it’s installed. If your mini-fridge still doesn’t cool, check out the next possible reason.

7. The start capacitor might be faulty

The purpose of the start capacitor is to assist the compressor to start up. If it stops working, the compressor won’t be able to start up, and your mini-fridge will fail to keep cool.

The start capacitor can be checked by following these steps:

1. Unplug your mini-fridge.
2. Locate the start capacitor (it’s connected to the compressor).
3. Test the start capacitor with your multimeter.
4. If the start capacitor doesn’t have continuity, it will need to be replaced. On the other hand, if it does have continuity, it’s working fine, and you can move on to check the next possible reason.
5. If you do replace the start capacitor, you’ll need to test if it has solved the cooling problem once it’s installed. If your mini-fridge still doesn’t cool, check out the next possible reason.

8. The thermistor might be defective

The thermistor in your fridge monitors the temperature and then informs the control board so that it knows what other components it needs to turn on or off to keep your fridge at the right temperature.

The thermistor can be checked by following these steps:

1. Unplug your mini-fridge.
2. Locate the thermistor (consult your user manual if you don’t know where to find it).
3. Test the thermistor with your multimeter.
4. If the thermistor doesn’t have continuity, it will need to be replaced. On the other hand, if it does have continuity, it’s working fine, and you can check the next possible reason.
5. If you do replace the thermistor, you’ll need to test if it has solved the cooling problem once it’s installed. If your mini-fridge still doesn’t cool, check out the next possible reason.

9. The main control board might be defective

The final possible reason your mini-fridge is not cooling is a faulty main control board. At this point, you can either replace the main control board and see if that fixes the problem or you might decide it’s a better option to buy a new mini-fridge.