Display shows E4; freezer may not enter or exit defrost properly, leading to frost buildup or warm temperatures.

Safety first: Unplug the freezer before accessing the evaporator, heater, or control board. Use insulated tools and wear gloves.

• Step 1 – Inspect evaporator frost pattern: Remove the rear interior panel. If the evaporator is completely encased in ice, the defrost system is likely not working.
• Step 2 – Manual defrost: As a temporary measure, unplug the unit and allow all ice to melt with the door open. Use towels to absorb water. Do not use sharp tools to chip ice.
• Step 3 – Visual check of heater: Locate the defrost heater at the base or wrapped around the evaporator. Look for breaks, burn marks, or disconnected wires.
• Step 4 – Check thermostat: The defrost thermostat is usually clipped to the evaporator tubing. Ensure it is firmly attached and the wires are intact.

Electrical testing of the heater and thermostat is required to confirm the failed part and should be performed by a technician. If both test good, the main control board’s defrost circuit may be defective.