Oven
F31
The F31 error code on a Neff oven indicates a fault with the oven’s temperature sensor (NTC sensor), meaning the oven cannot accurately read or regulate its internal temperature. It’s a moderately serious fault — the oven will typically stop heating or refuse to start as a safety precaution.
What does this error mean?
F31 signals that the oven’s electronic control board has detected an abnormal reading from the NTC (Negative Temperature Coefficient) temperature sensor inside the oven cavity. This sensor continuously feeds temperature data to the control board so the oven can maintain your selected heat. When the board receives a reading that’s out of range — too high, too low, or no signal at all — it throws the F31 code and locks out heating to prevent overheating or damage.
Est. repair cost
£15–£40 DIY sensor replacement; £80–£180 for a professional repair including labour
🔍 Likely causes
🛠️ Step-by-step fix
Step 1 – Hard reset the oven: Switch the oven off at the wall socket (or trip the circuit breaker), leave it completely unpowered for 5–10 minutes, then restore power. This clears transient software faults and costs nothing.
Step 2 – Check for visible soiling around the sensor: Open the oven and look for the NTC sensor probe — it’s usually a small metal rod protruding from the back wall of the oven cavity. If it’s heavily coated in grease or food residue, carefully clean it with a damp cloth and mild degreaser once the oven is completely cool.
Step 3 – Inspect the sensor probe for visible damage: With the oven unplugged, look closely at the sensor and its surrounding area for signs of burning, cracking, or corrosion. A visibly damaged probe will need replacing.
Step 4 – Check the sensor connector: Still with the oven unplugged, if you’re comfortable doing so, gently pull the oven away from the wall and locate the wiring connector at the back of the sensor. Press it firmly to reseat it. Do NOT open any sealed electrical enclosures — if the connector is inside the main body casing, stop here and call a professional.
Step 5 – Replace the NTC sensor (confident DIYers only): NTC sensors for Neff ovens are widely available online for £15–£40. They are typically held in place by one or two screws and plug in via a single connector. Always ensure the oven is fully isolated from the mains before attempting this. Use your model number (found on the oven door frame sticker) to source the correct part.
Step 6 – If the error persists after sensor replacement: The fault likely lies with the control board (PCB), which requires a qualified appliance engineer to diagnose and replace safely.
📞 When to call a professional
Call a qualified appliance engineer if the error returns after a hard reset and a clean, if you’re not confident isolating and working on mains-connected appliances, or if replacing the NTC sensor doesn’t resolve the fault. When you call, tell the engineer: ‘My Neff oven is showing error code F31 — I believe it’s a temperature sensor fault.’ This helps them bring the right parts and reduces call-out time.
⚖️ Repair or replace?
A professional repair for an F31 fault — typically sensor replacement or PCB repair — costs £80–£180 including labour in the UK. If your Neff oven is under 8 years old, repair is almost always the better financial decision given that Neff ovens retail from £500 upwards. If the oven is over 10 years old and the PCB needs replacing (parts alone can be £100–£200), replacement deserves serious consideration.