F6 error; unit may not defrost properly, leading to ice buildup on the back wall and poor cooling.

Safety first: Unplug the wine cooler. Be cautious around sharp evaporator fins and electrical connections.

Steps:

• 1. Inspect for heavy ice: Remove shelves and the rear interior panel. If the evaporator is a solid block of ice, defrost the unit completely before testing components.
• 2. Locate defrost heater: The heater is usually a metal or glass-encased element attached to or beneath the evaporator coil.
• 3. Test heater continuity: Disconnect heater leads and measure resistance with a multimeter. An open circuit indicates a failed heater.
• 4. Check thermal fuse/thermostat: If fitted, test the defrost safety thermostat or fuse in series with the heater. Replace if open.
• 5. Inspect wiring and connectors: Look for burnt connectors or damaged insulation around the heater circuit.
• 6. Replace faulty parts: Install a new Liebherr defrost heater and/or thermal fuse/thermostat as required, routing wires as originally installed.
• 7. Reassemble and test: Refit the panel, restore power, and monitor for normal defrost cycles over several days.

Warning: If the heater circuit is good but F6 remains, the main control board may not be initiating defrost and should be evaluated by a professional.