Kenmore freezer shows E4 and may not defrost; heavy frost accumulates on evaporator and back wall.

Safety first: Unplug the freezer before accessing the evaporator and defrost components. Beware of sharp fins and ice.

Steps to address E4:

• 1. Access evaporator compartment: Remove food and shelves as needed. Take off the rear interior panel to expose the evaporator coil.
• 2. Locate defrost thermostat/sensor: It is usually clipped to the evaporator tubing near the top or side, with two wires leading to the harness.
• 3. Check for physical damage: Look for a bulged, cracked, or burnt thermostat body. If the housing is deformed, it should be replaced.
• 4. Test continuity: With the freezer unplugged and the thermostat cold (below freezing), disconnect it and check continuity with a multimeter. It should read closed (near 0 ohms) when cold. If it is open when cold, it is defective.
• 5. Replace the part: If faulty, clip off the old thermostat and install the new Kenmore-compatible defrost thermostat or sensor. Use proper crimp connectors and heat-shrink tubing if splicing is required.
• 6. Defrost the evaporator: Allow all ice to melt using towels and a pan for water. Do not use sharp tools or open flames.
• 7. Reassemble and test: Reinstall the rear panel, restore power, and monitor for normal defrost operation over the next 24–48 hours. E4 should clear and frost buildup should not return quickly.

Note: If the thermostat tests good, the issue may be with the defrost heater or main control board, which may require professional diagnosis.