Is your refrigerator no longer getting cold at all, or not getting cold enough? This issue has a very diverse range of potential causes. Let's explore these together in order to get to the bottom of your problem.
THE POSSIBLE CAUSES FOR THIS ISSUE:
Before you do anything to your appliance, make sure you disconnect it from the power supply.
There is a risk of electric shock.
When a fridge will no longer get cold, or won't get cold enough, the thermostat can sometimes be the source of the problem. It's possible the thermostat is simply set at the wrong level. Therefore, try adjusting it to the right temperature. Once you've done this, check the setting by placing a thermometer in a glass of water inside the appliance for a few hours (ideally, the temperature should be between 2°C and 6°C). Thermostats can sometimes also develop faults. If this is the case with yours, the fridge may fail to get cold even though the thermostat is correctly set. If the thermostat doesn't appear to be working, despite your attempts to set it properly, you will need to consider replacing it.
When an excessively thick layer of frost builds up on the internal walls of a refrigerator, the appliance will have a difficult time getting and staying cold. The layer of frost will act as an insulator and prevent the fridge from operating efficiently. To avoid this problem, and resolve it if it occurs, make sure you regularly defrost your appliance.
Your fridge may be struggling to get cold due to a build-up of dust on and around the condenser, which is the grill located on the back of the appliance. When dust accumulates on this part of a fridge, it makes it difficult for the appliance to disperse the heat, causing the compressor to operate for longer periods than normal. Therefore, check that the grill on the back is in good condition and clean it regularly to ensure your fridge is able to operate at optimal efficiency.
On some fridges, the condenser is fitted with a fan that serves to optimise the efficiency of the thermal exchange process. If this fan fails or gets obstructed, such as by dust for example, the refrigerator will have a great deal of trouble maintaining itself at a cold temperature. If, upon inspection, the fan proves to be the cause of the problem, you will need to consider replacing it.
If the refrigerator isn't sealing hermetically, it will struggle to get cold. Check the condition of the door seal to ensure it isn't torn, distorted or worn anywhere. If it is, you will need to either replace it or adjust and realign it. If the door seal appears to be in good condition but the door is not closing tightly, the door itself may be the cause of the problem. If it's warped or distorted, air will seep into the fridge. Unfortunately, you will have no choice but to replace it if this turns out to be the case. One final thing to check is that none of the food items in the fridge are preventing the door from closing properly. Frost or ice can also cause this issue. Therefore, always remember to regularly defrost your appliance.
If the room where the refrigerator is located is excessively warm, this could prevent it from cooling efficiently. Has your appliance been placed next to a source of heat (such as a radiator or an oven) or in direct sunlight? If it has, consider moving it to a different location where these things will not be a factor.
The liquid coolant in your fridge is essential for keeping it cold. If the appliance will no longer get cold, or won't get cold enough, a leak in the cooling system could be the cause. This is not the type of problem you can resolve yourself. Employ the services of a professional to find the leak, repair it and refill the appliance with coolant.