Refrigerator shows E4 and there is heavy ice buildup on the evaporator or poor cooling.

Safety first: Unplug the refrigerator before accessing the evaporator or electrical components. Risk of electric shock and sharp metal edges.

Steps to address E4:

• 1. Manually defrost: Turn off and unplug the unit. Leave doors open for 24 hours to melt all ice. Do not chip ice with sharp tools to avoid damaging pipes.
• 2. Access the evaporator: Remove drawers and the rear inner panel of the freezer. Locate the defrost heater (usually a metal or glass tube or wire element at the base or around the evaporator) and the defrost thermostat/thermal fuse clipped to the evaporator.
• 3. Visual inspection: Look for broken heater elements, burnt spots, or disconnected wires. Check the thermostat body for cracks or signs of overheating.
• 4. Test the heater: With power off, disconnect the heater terminals and measure resistance. A typical heater will show a finite resistance (e.g., 50–300 Ω). An open circuit indicates a failed heater.
• 5. Test the defrost thermostat (if accessible): At freezer temperature, it should show continuity (closed). If it is open when cold, it is faulty.
• 6. Replace faulty components: Install a new Belling-compatible defrost heater and/or thermostat as required. Ensure all connections are secure and insulated.
• 7. Control board consideration: If heater and thermostat test good, the control board may not be energizing the heater. This requires professional testing and likely PCB replacement.

Warning: Working around the evaporator and sealed system requires care. If you see signs of refrigerant leakage (oil stains, hissing), stop and call a professional.