AGA range displays F3 and oven will not heat or stops mid-cycle

Safety first: Isolate the appliance from the mains power supply before removing any panels.

• Visual inspection: Locate the oven temperature sensor inside the cavity. Check for obvious damage, broken mounting, or exposed wires.
• Check rear connections: Remove the rear service panel of the AGA range. Find the two-wire sensor harness leading from the cavity to the control board. Ensure the connector is fully seated and not corroded or burnt.
• Continuity test: With the sensor unplugged, measure resistance across the sensor leads. If the meter shows an open circuit (OL) or extremely high resistance, the sensor is faulty and must be replaced.
• Inspect wiring: If the sensor tests good, inspect the harness from the sensor to the control board for cuts, chafing against the oven frame, or heat damage. Repair or replace damaged wiring using high-temperature-rated cable.
• Control board check: If the sensor and wiring are intact, the fault may be on the control board input. This typically requires board replacement by a professional.

When to call a technician: If you are not confident using a multimeter or accessing the rear of the cooker, arrange service with an AGA-authorised engineer.