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

Safety first: Isolate the appliance from the mains 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 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 sensor to 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 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.