Wine cooler beeps and shows E4; interior temperature may fluctuate or defrost may not work correctly.

Safety: Unplug the appliance. The defrost heater and wiring can be live and hot during operation.

• Access evaporator and defrost components: Remove interior shelves and the rear inner panel to expose the evaporator, defrost heater, and defrost sensor.
• Inspect defrost sensor: The defrost sensor is usually clipped to the evaporator tubing. Check for broken wires or a sensor that has come loose from the coil.
• Test defrost sensor: Disconnect the sensor and measure resistance at room temperature and again after gently warming it with your hand. Resistance should change smoothly. Replace if open, shorted, or non-responsive.
• Check defrost heater: With the unit unplugged, disconnect heater leads and measure resistance. A typical heater will show a finite resistance (often 50–300 Ω). If open (OL), replace the heater.
• Inspect thermal fuse/thermostat: Some Gorenje models include a thermal fuse or bimetal thermostat in series with the heater. Test for continuity; replace if open.
• PCB/relay check: If sensor and heater test good, the defrost relay or PCB may be faulty. Visually inspect for burnt spots or damaged components. PCB replacement is usually required if the relay is defective.
• Reassemble and test: After replacing faulty parts, reassemble panels, restore power, and monitor for normal defrost cycles and the absence of E4.