Cooker
F05
The F05 error code on a Smeg cooker indicates a fault with the oven’s temperature sensor (NTC probe) or its circuit — it’s a moderately serious fault that will prevent the oven from heating safely until resolved.
What does this error mean?
F05 signals that the oven’s internal temperature sensor (known as an NTC or thermocouple probe) is reading an out-of-range value — either implausibly high, implausibly low, or no signal at all. The oven’s control board uses this sensor to regulate heat accurately; when it detects a fault, it locks out the heating elements as a safety measure. This is an electrical oven fault, not a gas fault, and is found on Smeg’s electric and dual-fuel range cookers and built-in ovens.
Est. repair cost
£15–£35 DIY sensor replacement; £80–£150 professional repair; £180–£280 if PCB replacement is needed
🔍 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 restore power. If F05 clears and does not return, monitor for recurrence.
Check your Smeg oven manual for your specific model — some models allow you to enter a diagnostic or reset mode via the control panel. Refer to the model-specific instructions before proceeding.
Inspect the oven cavity visually for obvious grease build-up or spillages near the temperature sensor, which is usually a small metal probe mounted on the rear or side wall of the oven interior. Clean carefully with a damp cloth (oven cold and unplugged) to remove any conductive residue around it.
Check the sensor probe for visible damage — a cracked ceramic tip, burn marks, or a probe that has come away from its mounting bracket all indicate the sensor needs replacing. Replacement NTC sensors for Smeg ovens are widely available from UK appliance parts suppliers (e.g. 4ourhouse, Espares) for £15–£35.
If you are confident working with appliances, disconnect the oven from power, access the sensor (usually two screws and a single connector), and replace it like-for-like using your model number to source the correct part. Refit, restore power, and test.
If the error persists after sensor replacement, or if you see any burnt wiring, do not proceed further — this points to a wiring harness or control board fault that requires a qualified appliance engineer.
📞 When to call a professional
If replacing the NTC sensor yourself does not clear the F05 code, or if you notice any burnt or damaged wiring during inspection, stop and call a qualified appliance repair engineer. Tell them: ‘My Smeg oven is showing error code F05 — I believe it’s a temperature sensor or PCB fault.’ Most reputable engineers will diagnose for a fixed call-out fee and quote before proceeding.
⚖️ Repair or replace?
A professional repair for F05 — covering diagnosis, sensor replacement, and labour — typically costs £80–£150 in the UK; a PCB replacement will push this to £180–£280. If your Smeg oven is under 8 years old and otherwise in good condition, repair is almost always the better value. For ovens over 10 years old where the repair cost exceeds 50% of a comparable new appliance, replacement is worth considering — entry-level Smeg electric ovens start around £400–£500.