F08 error displayed, heavy frost on evaporator, poor cooling, fan may be noisy or blocked.

Safety first: Unplug the refrigerator. The defrost heater operates at mains voltage and can be hazardous.

Step-by-step checks:

• 1. Access evaporator and heater: Remove freezer drawers and rear inner panel to expose the evaporator and heater element (often a metal or glass-tube heater at the base or woven through the coil).
• 2. Visual inspection: Look for burnt spots, broken heater tubes, or disconnected wires. Check the thermal fuse/thermostat clipped to the evaporator.
• 3. Continuity test: Disconnect heater terminals and measure resistance. An open circuit indicates a failed heater. Similarly, test the thermal fuse/defrost thermostat for continuity at freezing temperatures.
• 4. Replace faulty components: Install a new Indesit-compatible defrost heater and/or thermal fuse/thermostat as required. Ensure all connections are tight and insulated.
• 5. Manual defrost: Fully defrost the evaporator before reassembly to restore airflow.

When to call a technician: If heater and safety devices are good but F08 persists, the control board defrost relay or triac may be faulty and should be checked by a professional.