If a freezer has ice all over and the lower compartment does not cool, it is likely experiencing a defrost problem. When the freezer's defrost system malfunctions, it can lead to excessive ice buildup on the evaporator coils. This ice accumulation prevents proper airflow and heat transfer, resulting in the lower compartment not cooling effectively.
The most common causes of this issue are:
Defrost Timer Failure: The defrost timer is responsible for initiating regular defrost cycles to melt ice on the evaporator coils. If the timer fails, the defrost cycles may not occur, leading to excessive ice buildup.
Defrost Heater Failure: The defrost heater is responsible for melting the ice on the evaporator coils during defrost cycles. If the heater is faulty, it won't be able to effectively thaw the ice, leading to ice accumulation.
Defrost Thermostat Failure: The defrost thermostat monitors the temperature of the evaporator coils and activates the defrost heater when necessary. If the thermostat is faulty, it may not signal the heater to turn on, resulting in ice buildup.
Blocked or Malfunctioning Evaporator Fan: The evaporator fan is responsible for circulating cold air throughout the freezer. If the fan is blocked or not working correctly, it can lead to uneven cooling and ice formation.
Door Seal Issues: If the freezer door doesn't seal properly, warm air from the outside can enter the freezer, leading to increased moisture and ice buildup.
To resolve this problem, you should first try manually defrosting the freezer by turning it off and letting the ice melt. Once defrosted, check the defrost timer, heater, thermostat, and evaporator fan for any signs of malfunction. If you're not familiar with appliance repairs, it's best to consult a professional technician to diagnose and fix the issue properly. Always ensure the freezer is unplugged before attempting any repairs.