Wine cooler displays E4 and may stop cooling or run erratically.

Safety warning: Unplug the appliance before accessing the evaporator or control board. Defrost heaters and wiring can be hot immediately after a defrost cycle.

How to proceed:

• 1. Inspect for heavy frost: Remove interior rear panel and check the evaporator. A solid block of ice indicates a defrost system problem.
• 2. Check defrost sensor: Locate the defrost sensor clipped to the evaporator tubing. Inspect for broken wires or corrosion. Test resistance with a multimeter; compare to Electrolux specs. Replace if open/shorted.
• 3. Test defrost heater (if accessible): With the unit unplugged, disconnect heater leads and measure resistance. A typical heater will show a finite resistance (often 50–300 ohms). An open circuit indicates a failed heater.
• 4. Examine wiring and connectors: Look for burnt connectors, melted insulation, or loose plugs between the heater/sensor and the control board.
• 5. Manual defrost: As a temporary measure, allow the unit to defrost fully by leaving the door open and unplugged for 24 hours, protecting the floor from water. This may restore cooling temporarily but does not fix the underlying issue.

When to call a technician: If the heater and sensor test good, the defrost relay or control board is likely faulty. Board-level diagnosis and replacement should be done by a qualified technician.