Oven
F03
The F03 error code on an Indesit oven indicates a fault with the oven temperature sensor (NTC probe) — it’s one of the most common oven faults and is usually straightforward to diagnose, though it does require a part replacement in most cases.
What does this error mean?
F03 means the oven’s control board is detecting an open circuit or abnormal resistance reading from the NTC temperature sensor, which monitors the internal oven cavity temperature. Without a reliable temperature reading, the oven cannot regulate heat safely and will shut down or refuse to start. This is a protective fault — the oven is doing the right thing by stopping rather than overheating.
Est. repair cost
£10–£25 DIY sensor replacement; £80–£180 for a professional repair including parts and labour
🔍 Likely causes
🛠️ Step-by-step fix
Power off and unplug the oven at the wall socket — never work on the appliance with it live. Leave it for 10 minutes to cool fully.
Perform a hard reset: with the oven unplugged for 5–10 minutes, plug it back in and power on. If F03 clears temporarily, you have an intermittent sensor or connection issue, not a permanent failure.
Locate the NTC temperature sensor — on most Indesit fan ovens it sits at the back of the oven cavity, visible as a small metal probe with a two-wire connector. Check the connector is firmly seated and that the wires show no obvious burn marks or breaks.
Test the sensor resistance with a multimeter (set to Ohms). At room temperature (~20°C), a healthy Indesit NTC sensor typically reads around 990–1010Ω. A reading of infinite (OL) or zero confirms a faulty sensor.
Order a replacement NTC sensor using your oven’s full model number (found on the rating plate inside the door frame). Sensors typically cost £10–£25 from UK parts suppliers such as eSpares or 4ourhouse. Fitting requires removing one or two screws and swapping the connector — no specialist tools needed.
After fitting the new sensor, restore power and run the oven at 180°C for 15 minutes to confirm the error has cleared and the oven heats correctly.
📞 When to call a professional
If the sensor tests healthy but F03 persists, the fault likely lies with the wiring harness or the main control board — both require a qualified appliance engineer to diagnose safely. Call an engineer and tell them: ‘My Indesit oven is showing error code F03, the NTC sensor has been checked or replaced, and the fault remains.’ This will save diagnostic time and may reduce your call-out cost.
⚖️ Repair or replace?
A professional repair for an F03 fault — including a control board replacement if needed — typically costs £80–£180 in the UK including parts and labour. If your oven is under 7 years old, repair is almost always the better value. For ovens 8 years or older, weigh the repair cost against a new built-in oven starting from around £250–£350; if the repair quote exceeds 50% of replacement cost, replacing is the smarter financial decision.