Safety: Unplug the wine cooler and allow ice to melt before working near the evaporator and heater.

Access defrost components: Remove interior shelves and the rear inner panel to expose the evaporator, defrost heater, and defrost thermostat (usually a round or oval device clipped to the coil).
Check thermostat position: Ensure the thermostat is firmly clipped to the evaporator tubing so it senses temperature correctly.
Test thermostat: With the unit at room temperature, measure continuity across the thermostat. Many are closed when cold and open when warm; test again when chilled (place in ice water) to verify operation. Replace if it does not switch as specified.
Inspect wiring: Look for brittle or burned wires around the heater and thermostat. Repair or replace damaged sections.
Replace thermostat: Install a compatible Blomberg defrost thermostat, clip it securely to the evaporator, and reconnect wiring.
Control board: If the thermostat and heater are good but E9 persists, the main PCB defrost circuit may be faulty and require replacement.

Display shows E9; unit may not defrost properly and frost accumulates on the evaporator.

Possible Causes