Error F5 appears and the refrigerator may not defrost, or may over-defrost causing temperature swings.

Safety: Unplug the refrigerator before accessing the freezer evaporator area. The defrost heater operates at mains voltage.

Steps:

• 1. Access evaporator and heater: Remove freezer contents and the rear interior panel to expose the evaporator coil and defrost heater (usually a metal or glass-encased element at the bottom or woven through the coil).
• 2. Visual inspection: Look for burnt spots, broken heater sections, or melted connectors.
• 3. Test heater continuity: Disconnect heater wires. Using a multimeter on continuity or ohms, check across the heater terminals. A good heater typically shows low resistance (e.g., 20–150 Ω). If open (OL), replace the heater.
• 4. Check defrost thermostat/thermal fuse: Locate the thermostat clipped to the evaporator tubing. At freezing temperatures, it should show continuity. If it remains open when cold, replace it.
• 5. Inspect wiring and connectors: Repair any burnt or loose connectors with high-temperature-rated terminals.
• 6. Control board: If heater and thermostat test good, the main control board’s defrost relay or triac may be faulty. Board replacement is typically required.

Note: After replacing heater or thermostat, ensure all wiring is secured away from sharp metal edges and moving parts.