Oven
F33
The F33 error code on an AEG oven indicates a fault with the oven’s temperature sensor (NTC probe) circuit — specifically, the sensor is reading a value that is too high or outside the expected range. It’s a moderately serious fault that will prevent the oven from heating safely until it’s resolved.
What does this error mean?
Your AEG oven constantly monitors its internal temperature using an NTC (Negative Temperature Coefficient) sensor. The F33 code means the control board is receiving a signal from that sensor that is abnormally high — either the sensor itself is faulty, or there’s a wiring issue causing a misleading reading. Because the oven cannot confirm the actual temperature, it shuts down the heating element as a safety measure to prevent overheating.
Est. repair cost
£15–£40 DIY (NTC sensor replacement); £80–£180 for a professional repair including callout and parts
🔍 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 F33 clears and does not return, the fault was a temporary glitch.
Step 2 – Clean the oven cavity: Grease and food debris can cause hotspots. Run a manual clean cycle or wipe down the interior thoroughly, paying attention to any areas near the back wall where the sensor probe is located.
Step 3 – Locate and visually inspect the NTC sensor: The sensor is usually a small metal probe mounted on the back interior wall of the oven cavity. With the oven unplugged, check whether it looks visibly burnt, corroded, or physically damaged.
Step 4 – Check the sensor wiring: With the oven still unplugged, gently trace the wiring from the sensor back through the oven. Look for any melted insulation, pinched wires, or loose push-fit connectors. Reseat any loose connectors firmly.
Step 5 – Test or replace the NTC sensor: AEG oven NTC sensors can be tested with a multimeter (should read approx. 1000 ohms at room temperature). If the reading is open-circuit or wildly out of range, the sensor needs replacing. Genuine or compatible AEG NTC sensors are widely available online for £15–£40 and are a straightforward DIY replacement — just unplug the old one and plug in the new one.
Step 6 – If F33 persists after sensor replacement: Do not attempt to open or replace the control board yourself. This requires a qualified appliance engineer.
📞 When to call a professional
If replacing the NTC sensor does not clear the F33 code, the fault is likely within the main control board (PCB) — this is not a DIY job. Call a qualified appliance repair engineer and tell them: ‘My AEG oven is showing error code F33, I’ve already replaced the NTC temperature sensor and the fault persists, so I suspect a PCB fault.’ This will save diagnostic time and money.
⚖️ Repair or replace?
A professional repair for an F33 fault — covering callout, diagnosis, and parts — typically costs £80–£180 in the UK. If your oven is under 7 years old and otherwise in good condition, repair is almost always worth it. For ovens over 10 years old, weigh the repair cost against a new built-in oven (£300–£700 fitted), especially if other components are showing wear.