AGA gas oven not heating or heating very slowly; the burner does not stay lit.

Safety first: Turn off the gas and power before removing oven panels. If you smell gas, ventilate and call a gas engineer immediately.

• Observe ignition: Through the inspection window or with the base panel removed (if design allows), watch the burner during ignition. If it lights briefly then goes out, the flame sensor/thermocouple may be faulty.
• Clean burner: Remove the oven base and burner (if accessible) and clean the ports with a soft brush. Do not enlarge the ports.
• Check regulator and supply: Ensure the external gas regulator is correct for your gas type and that the supply pressure is within AGA specifications (requires a manometer and a gas engineer).

When to call a technician: Gas oven burner, thermocouple, and valve diagnosis must be performed by a qualified gas-safe engineer.