If your chest freezer is not cooling after being unplugged for an extended period of time, there could be a few potential reasons for this issue:
Insufficient time to cool: Freezers typically require several hours to reach their optimal cooling temperature after being unplugged. Make sure you have allowed enough time for the freezer to cool down before assessing its cooling performance.
Malfunctioning compressor: The compressor is responsible for circulating refrigerant and cooling the freezer. If the compressor is faulty or damaged, it may not be able to properly cool the freezer. A professional technician will need to inspect and repair or replace the compressor if necessary.
Lack of refrigerant: If there is a refrigerant leak or the freezer has lost its refrigerant charge, it will not be able to cool effectively. This is a serious issue and should be addressed by a professional technician who can identify the source of the leak, repair it, and recharge the system with the appropriate amount of refrigerant.
Thermostat or temperature control issue: The thermostat or temperature control mechanism in the freezer may be faulty, preventing it from properly regulating the cooling cycle. This can result in the freezer not cooling or maintaining the desired temperature. A technician can diagnose the issue and replace the faulty component if needed.
Blocked or dirty condenser coils: Over time, condenser coils can accumulate dust, dirt, and debris, hindering the heat exchange process and causing the freezer to lose its cooling efficiency. Cleaning the condenser coils can often resolve this issue. Refer to the freezer's manual or consult a professional on the proper procedure for cleaning the coils.
If you have tried troubleshooting the basic steps and the freezer is still not cooling, it's best to contact a qualified appliance repair technician. They will have the expertise and tools to diagnose the specific problem with your freezer and recommend the appropriate course of action.