Refrigerator not cooling correctly, display shows F03, compressor may run continuously or not at all.

Safety first: Unplug the appliance before accessing sensors or control boards.

Step-by-step checks:

• 1. Locate the fridge sensor: In many Indesit refrigerators, the fridge NTC is behind a small plastic cover on the rear wall or ceiling of the fresh-food compartment.
• 2. Visual inspection: Remove the cover and inspect the sensor and wiring for moisture damage, corrosion, or broken insulation.
• 3. Resistance test (for qualified users): Disconnect the sensor from the harness and measure its resistance with a multimeter. At around 25°C, most NTCs read between 4–10 kΩ (check service data for your model). Infinite resistance indicates open circuit; near 0 Ω indicates a short.
• 4. Replace the NTC sensor: If readings are out of range, replace the sensor with the correct Indesit fridge NTC probe. Route the new sensor along the original path and ensure good contact with the wall channel.
• 5. Check harness to PCB: If the sensor tests good, inspect the harness from the sensor to the main PCB for pinched or broken wires, especially at hinge points and behind the liner.

When to call a technician: If the sensor and wiring are good but F03 persists, the main control board may be faulty and should be tested/replaced by a professional.