Oven
F4
The F4 error code on a Miele oven indicates a fault with the oven temperature sensor (NTC sensor), meaning the oven cannot reliably monitor or regulate its internal temperature. This fault will prevent the oven from heating correctly and should be addressed promptly to avoid further damage.
What does this error mean?
Miele ovens use an NTC (Negative Temperature Coefficient) sensor to continuously measure the temperature inside the cavity and relay that information to the control board. An F4 code means the control board is receiving a signal from that sensor that is out of the expected range — either an open circuit (no signal) or a short circuit (constant signal). In plain terms, the oven has lost confidence in its ability to measure heat safely, so it shuts down the heating function as a precaution.
Est. repair cost
£15–£40 DIY sensor replacement; £80–£180 professional repair (sensor or PCB diagnosis); £150–£300+ for PCB replacement parts alone
🔍 Likely causes
🛠️ Step-by-step fix
Power cycle the oven: switch it off at the wall socket or isolate it at the fuse board, wait 5 minutes, then switch back on. A one-off software glitch can occasionally trigger F4, and a full reset clears it.
Check the error is persistent: run a short bake cycle and see if F4 returns immediately. If it does, the fault is real and not a transient glitch.
Inspect the sensor connector (visual only, no tools): with the oven completely unplugged and cooled down, remove the back panel of the oven cavity (two or four screws). Locate the NTC sensor — a small metal probe mounted in the cavity wall — and check whether its connector is visibly loose, burnt, or corroded. Re-seat the connector firmly if it appears loose.
Test the NTC sensor resistance: with the oven unplugged and cooled to room temperature (~20°C), disconnect the sensor and use a multimeter set to resistance (Ohms). A healthy Miele NTC sensor typically reads around 4,000–6,000 Ohms at room temperature. A reading of zero (short) or infinite resistance (open circuit) confirms a failed sensor.
Replace the NTC sensor if faulty: Miele NTC sensors are available from UK Miele spares suppliers (e.g. espares.co.uk, 4miele.co.uk) for £15–£40. Note your full model number from the rating plate inside the door frame to order the correct part. Fitting involves removing two screws and swapping the connector — no specialist knowledge required.
If replacing the sensor does not clear F4, stop DIY work: the control board (PCB) is likely at fault. This requires professional diagnosis and component-level repair or replacement.
📞 When to call a professional
If the F4 error returns after replacing the NTC sensor, or if you find burnt wiring rather than a simple loose connector, stop and contact a Miele-approved service engineer or a reputable independent appliance repair technician. Tell them: ‘My Miele oven is displaying an F4 fault code — I’ve already replaced the NTC temperature sensor and the fault persists, so I suspect a control board issue.’ This saves diagnostic time and money.
⚖️ Repair or replace?
A professional repair for an F4 fault — covering sensor replacement or PCB diagnosis — typically costs £80–£180 in the UK including parts and labour. If your Miele oven is under 8 years old, repair is almost always the right call: Miele appliances are built to last 20 years and replacement costs £600–£2,000+. If the oven is over 10–12 years old and the PCB needs replacing (parts alone can be £150–£300), get a quote first and weigh it against a new mid-range Miele oven.