How to Fix / Troubleshooting

Safety first: Turn off power and let the oven cool completely.

Locate secondary sensor: On some AEG ovens, a second NTC sensor is fitted near the top or rear of the cavity, separate from the main sensor. Refer to the service diagram if available.
Measure resistance: Disconnect the sensor and measure its resistance at room temperature. Compare with the main sensor; they should be similar. Replace if open, shorted, or significantly different.
Check mounting: Ensure the sensor is firmly fixed to the cavity wall and not hanging loose, which can cause incorrect readings.
Inspect wiring: Follow the harness back to the control board, checking for heat damage or loose connectors.
Control board diagnosis: If both sensors and wiring are good, the control board’s sensor input may be faulty and require replacement.

Warning: Do not run pyrolytic cleaning cycles until this fault is resolved; excessive temperatures can be hazardous.

F9 error displayed, oven may not start or may shut down when high temperatures are selected.

Possible Causes