Freezer displays F05 and may not defrost; heavy ice forms on the evaporator and airflow is restricted.

Safety first: Disconnect from mains and protect the floor from melting ice.

Access the evaporator and heater:

• Remove internal drawers and rear liner panel to expose the evaporator coil.
• The defrost heater is usually a metal or glass-encased element fixed along the bottom or woven through the evaporator.

Testing the heater:

• Disconnect the heater connectors.
• Measure resistance across the heater terminals. A typical reading is between 50–300 Ω depending on model. Infinite resistance indicates an open heater.
• Inspect terminals for burning or loose crimp connections.

Check wiring and relay:

• Trace the heater wires back towards the main PCB, checking for cuts or chafing.
• If you have access to the wiring diagram, identify the defrost relay on the PCB and inspect for burn marks or cracked solder joints.

Repair:

• Replace a failed defrost heater with the exact Indesit heater assembly for your model.
• Repair or replace any damaged wiring using high-temperature-rated cable and proper insulated connectors.
• If the relay on the PCB is visibly damaged or does not switch (requires advanced testing), the main control board may need replacement.