AGA oven displays F3 and will not start a cooking cycle; sometimes appears after a power cut.

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

• Reset after power cut: Turn off power for 5 minutes, then restore. If F3 appears immediately, proceed with hardware checks.
• Check sensor connection at cavity: Remove the sensor mounting screws inside the oven and gently pull the sensor forward. Confirm the connector is fully seated and not corroded.
• Check continuity: With the sensor disconnected at both ends (cavity and control board), test continuity of each conductor in the harness. Repair or replace the harness if open.
• Test the sensor itself: Measure resistance across the sensor. An infinite reading (open circuit) indicates a failed sensor that must be replaced.
• Inspect control board connector: Remove the control panel, locate the sensor connector on the main PCB, and check for cracked solder joints or burnt pins. Reseat the connector.

Note: If wiring and sensor are confirmed good but F3 remains, the control PCB may be misreading the circuit and should be replaced by a qualified technician.