Oven
F35
The F35 error code on an AEG oven points to a fault with the oven’s temperature sensor or its circuit — it’s one of the more common faults on AEG electric ovens and, in many cases, is fixable without a call-out charge.
What does this error mean?
The F35 code tells you the oven’s control board has detected an abnormal reading from the temperature sensor (also called the NTC probe or thermostat sensor). This usually means the sensor is reading temperatures outside the expected range — either implausibly high, implausibly low, or not reading at all. The oven will typically cut out or refuse to heat as a safety measure to prevent overheating or incorrect cooking temperatures.
Est. repair cost
£15–£35 DIY sensor replacement; £80–£160 professional repair including call-out
🔍 Likely causes
🛠️ Step-by-step fix
Step 1 – Hard reset: Switch the oven off at the wall socket (or trip the circuit breaker), wait 5 minutes, then restore power. Restart the oven and check whether F35 has cleared. A power surge can trigger a false fault.
Step 2 – Check the oven manual: Confirm F35 is listed as a temperature sensor fault in your specific AEG model’s manual. AEG’s code definitions can vary slightly between model series. Download the manual free from AEG’s UK support site if you don’t have a physical copy.
Step 3 – Inspect the sensor probe: With the oven completely cool and unplugged from the mains, open the oven door and look for the temperature sensor — it’s usually a small metal probe mounted on the back wall of the oven cavity. Check it isn’t visibly damaged, bent out of position, or coated in heavy grease or carbon build-up. Gently clean around it with a damp cloth if needed.
Step 4 – Check the sensor connector: Still with the oven unplugged, carefully pull the oven away from its housing to access the back panel (if a built-in model, skip this unless you’re confident). Check the wiring connector running to the sensor for any obvious looseness, burn marks, or corrosion. Firmly reseat any loose connector.
Step 5 – Replace the NTC temperature sensor: If the reset didn’t work and the probe looks suspect, the sensor itself is almost certainly the culprit. AEG NTC sensors are widely available online (search your full model number). Replacement is a straightforward two-screw job on most models — unplug the connector, remove two screws, fit the new sensor, reconnect. Cost: £15–£35 for the part.
Step 6 – Stop here if unsure: If replacing the sensor doesn’t clear the fault, the issue is likely the wiring harness or control board. Do not attempt to repair these yourself — call a qualified appliance engineer.
📞 When to call a professional
If the fault persists after a reset and a sensor replacement, call a registered appliance engineer — the wiring harness or control board will need professional diagnosis. When you call, give them your full AEG model number (found on the frame inside the oven door) and tell them you’ve already reset the oven and replaced or inspected the NTC sensor — this saves time and money on the call-out.
⚖️ Repair or replace?
A professional repair for F35 typically costs £80–£160 depending on whether it’s a sensor swap or a control board replacement (boards alone can cost £60–£120 in parts). If your AEG oven is under 8 years old, repair almost always makes financial sense. If it’s over 10 years old and the control board has failed, a new mid-range AEG oven (£400–£700) is often better value than a £150+ board repair on ageing hardware.