Wine cooler displays E4 and may shut down cooling or run continuously; defrost may not function correctly on compressor-based models.

Safety warning: Unplug the unit before accessing the evaporator or defrost components. Surfaces may be sharp and may have ice buildup.

Steps to address E4:

• Defrost the unit: With the cooler unplugged, open the door and allow all ice to melt from the evaporator area. Place towels to catch water. Do not chip ice with sharp tools.
• Access evaporator and defrost components: Remove the interior rear panel to expose the evaporator coil. Locate the defrost sensor/thermistor and any inline defrost thermostat or thermal fuse attached to the coil or tubing.
• Inspect wiring: Look for burned, brittle, or broken wires around the defrost heater and sensors. Check connectors for corrosion.
• Test defrost thermistor: Disconnect and measure resistance with a multimeter. Compare to expected NTC values at known temperatures (e.g., in ice water ~32°F / 0°C). Replace if open, shorted, or out of spec.
• Test defrost heater and thermostat: With the unit unplugged, check continuity through the defrost heater and any defrost thermostat/thermal fuse. An open circuit indicates a failed component.
• Replace faulty parts: Install a new defrost sensor (thermistor), defrost heater, or defrost thermostat/thermal fuse as needed, using OEM or compatible Kenmore parts. Secure them in the original positions on the evaporator.
• Reassemble and test: Reinstall the interior panel, restore power, and monitor operation over 24 hours to ensure E4 does not return and frost does not build excessively.

Note: If all defrost components test good, the main control board's defrost circuit may be defective and require professional replacement.