Indesit oven display shows F04 and oven will not start heating, sometimes after a power surge

Safety: Disconnect mains power before removing panels.

Steps:

• 1. Inspect sensor and wiring: Follow the oven temperature sensor leads from the cavity to the control board. Look for crushed insulation where the harness passes through the rear panel.
• 2. Check for shorts: With the sensor unplugged, measure resistance from each sensor lead to the oven chassis. Any low resistance indicates a short to earth; repair or replace the harness.
• 3. Dry connectors: If the cooker has recently been steam-cleaned or exposed to moisture, unplug the sensor connector and dry it thoroughly. Lightly clean with electrical contact cleaner if available.
• 4. Replace sensor if readings are abnormal: If the sensor resistance is far outside the specified range at room temperature, fit a new Indesit-compatible sensor.
• 5. Control board check: If wiring and sensor are good but F04 persists, the main control board input may be damaged. Board replacement is usually required and is best done by a professional.