Oven
F5
The F5 error code on a Zanussi oven indicates a fault with the oven’s temperature sensor (NTC probe) or its associated wiring. It’s a moderately serious fault — your oven will typically stop heating and lock itself out until the issue is resolved.
What does this error mean?
The F5 code means your Zanussi oven’s control board has detected an abnormal signal from the NTC (Negative Temperature Coefficient) temperature sensor — the component that monitors the oven cavity temperature in real time. This could mean the sensor is reading impossibly high or low temperatures, or has stopped sending a signal entirely. Without a reliable temperature reading, the oven shuts down as a safety precaution to prevent overheating or uncontrolled heating.
Est. repair cost
£15–£35 DIY (NTC sensor part only); £80–£160 professional repair; £150–£250 if PCB replacement is needed
🔍 Likely causes
🛠️ Step-by-step fix
Power reset first: switch the oven off at the wall socket (or trip the circuit breaker), wait 5 minutes, then restore power. If F5 clears and doesn’t return, it was a temporary glitch — monitor it closely.
Check the cooling fan vents (usually at the rear or top of the oven): ensure they’re not blocked by grease build-up or debris. Clean with a dry cloth if needed. A blocked fan causes the cavity to overheat and can trigger F5.
Locate the NTC temperature sensor: it’s usually a small probe mounted through the back wall of the oven cavity, secured by one or two screws. With the oven fully unplugged, gently pull the probe and inspect it visually for burn marks, cracks, or corrosion.
Test the NTC sensor with a multimeter (set to resistance/ohms): a healthy Zanussi NTC sensor typically reads around 1,000 ohms (1kΩ) at room temperature (~20–25°C). A reading of 0 (short circuit) or OL/infinite (open circuit) confirms the sensor has failed and needs replacing.
If the sensor tests faulty, order a genuine or compatible replacement NTC probe for your specific Zanussi model (check the model number on the oven door frame). Fit it yourself — it requires only a screwdriver, no electrical work inside the control board. Reconnect, restore power, and test.
If the sensor tests fine, inspect the wiring connector between the sensor and the control board for loose pins, corrosion, or heat damage. A faulty connector can be carefully reseated or replaced — if the wiring harness itself is burnt, stop and call a professional.
📞 When to call a professional
Call a qualified appliance engineer if replacing the NTC sensor does not clear the F5 error, as the fault likely lies with the main PCB (control board) — a repair that involves working inside the oven’s electrical housing and is not DIY-safe. Also call if you find burnt or melted wiring inside the appliance. Tell the engineer: ‘My Zanussi oven is displaying F5 — I’ve already ruled out the NTC temperature sensor and need the wiring harness or PCB diagnosed.’
⚖️ Repair or replace?
A DIY NTC sensor replacement is the cheapest route at £15–£35 for the part. A professional repair — covering callout, diagnosis, and labour — typically runs £80–£160; a PCB replacement can push this to £150–£250 depending on the model. If your Zanussi oven is over 8–10 years old and the repair cost exceeds 50% of a comparable new oven (budget models start around £300–£400), replacement is the more sensible investment.