Display shows E5 and the wine cooler may not defrost properly, leading to ice buildup and poor cooling.

Safety first: Unplug the wine cooler before testing any heater or thermostat. The defrost heater operates at mains voltage.

• 1. Check for ice buildup: Inspect the back interior wall for thick frost. If heavily iced, manually defrost the unit by unplugging and leaving the door open until all ice melts.
• 2. Access evaporator and heater: Remove shelves and the inner rear panel to expose the evaporator and defrost heater (usually a metal or glass-encased element beneath or around the coil).
• 3. Test defrost heater: Disconnect heater leads and measure resistance with a multimeter. A typical heater will show finite resistance (e.g., 50–300 Ω). If it reads open (OL), replace the defrost heater.
• 4. Check defrost thermostat/thermal fuse: Locate the defrost thermostat or thermal fuse clipped to the evaporator tubing. Test for continuity at freezing temperatures. Replace if open when it should be closed.
• 5. Inspect wiring and connectors: Look for burnt connectors or discolored wires in the defrost circuit. Repair or replace as needed.
• 6. Main PCB check: If heater and safety devices test good, the defrost relay or control logic on the main PCB may be faulty and require board replacement.

Note: After repairs, reassemble panels carefully to avoid air leaks that can cause repeat frost issues.