Oven
F23
The F23 error code on an AEG oven indicates a fault with the oven’s temperature sensor (NTC sensor) circuit — either the sensor itself has failed or there’s a wiring issue between the sensor and the control board. It’s not a dangerous fault, but your oven will likely be locked out and unusable until it’s resolved.
What does this error mean?
F23 means the oven’s control board is detecting an abnormal signal from the temperature sensor — specifically, it’s reading a value that is too high, suggesting either a short circuit in the sensor circuit or a sensor that has completely failed. The oven uses this sensor to regulate temperature accurately, so when the signal is out of range, it shuts down to prevent overheating. This is a protective measure, not a sign of catastrophic damage.
Est. repair cost
£15–£35 DIY (replacement NTC sensor) or £80–£180 for professional repair including parts and labour
🔍 Likely causes
🛠️ Step-by-step fix
Step 1 — Reset the oven: Switch the oven off at the wall socket or trip the circuit breaker, wait 5 minutes, then restore power. If F23 clears, monitor closely; if it returns, move to the next steps.
Step 2 — Check the sensor visually (oven cold and unplugged): Remove the back panel inside the oven cavity (usually held by two screws). Inspect the temperature sensor — a small probe, typically mounted at the top-rear or side wall — for any obvious burn marks, cracks, or physical damage.
Step 3 — Test the sensor with a multimeter (oven unplugged): Disconnect the sensor plug and measure resistance across the sensor terminals. At room temperature (~20°C), an AEG NTC sensor should read approximately 4,000–6,000 ohms. A reading of zero (short circuit) or infinite resistance (open circuit) confirms a faulty sensor.
Step 4 — Inspect the wiring harness: With the oven still unplugged, trace the sensor cable back toward the control board and look for any sections with melted insulation, pinch points, or burnt connectors. Wiggle connectors gently to check for loose contacts.
Step 5 — Replace the NTC temperature sensor: Order a compatible AEG replacement sensor using your oven’s full model number (found on the rating plate inside the door frame). Sensors are straightforward to swap — unplug the connector, unscrew the bracket, fit the new sensor, and reassemble. This is a safe DIY task.
Step 6 — If fault persists after sensor replacement: Do not attempt to repair or replace the control board yourself, as this involves working with mains-connected electrical components. Call a qualified appliance engineer at this point.
📞 When to call a professional
If replacing the temperature sensor does not clear the F23 code, the fault is most likely in the wiring harness or the main control board (PCB) — both of which require a qualified appliance engineer to diagnose and replace safely. When calling, tell the engineer you have an AEG electric oven showing error code F23, that you’ve already replaced the NTC sensor, and that the fault persists. This will help them come prepared with the right parts.
⚖️ Repair or replace?
A professional repair for an F23 fault typically costs £80–£180 depending on whether the issue is wiring (cheaper) or a control board replacement (more expensive). If your AEG oven is over 8–10 years old, a control board repair may not be economical — a new mid-range AEG or equivalent oven starts at around £350–£500. For ovens under 7 years old in otherwise good condition, repair is almost always the better value.