Tumble Dryer
F04
The F04 error code on a Hoover tumble dryer signals a fault with the NTC temperature sensor — the component that monitors internal drum temperature. It’s a moderately serious fault: your dryer will stop mid-cycle to protect against overheating, but in many cases it’s fixable without calling an engineer.
What does this error mean?
The F04 code tells you the control board has detected an abnormal reading from the NTC (Negative Temperature Coefficient) thermistor, the sensor that continuously checks the air temperature inside the drum. Either the sensor is reading too high, too low, or sending no signal at all. The machine cuts out as a safety measure to prevent a fire or damage to your laundry and drum components.
Est. repair cost
£10–£25 DIY (NTC sensor part only); £80–£130 professional sensor repair; £150–£250 if control board replacement needed
🔍 Likely causes
🛠️ Step-by-step fix
Power off and reset: Switch the dryer off at the plug, wait 10 minutes, then plug back in and restart a short cycle. A temporary sensor glitch can clear itself after a full power-down.
Clean the lint filter: Remove the filter (usually inside the door lip), peel off all lint, and rinse under the tap if needed. A blocked filter is one of the most common causes of overheating faults. Dry it fully before reinserting.
Clean the condenser unit: On condenser and heat pump models, unlatch the condenser drawer at the bottom of the machine, remove the condenser block, and rinse it thoroughly under the tap until water runs clear. Let it dry before refitting. Do this every 1–2 months.
Check for overloading: Reduce your load to no more than the drum’s rated capacity (check your model’s manual). Overloading traps heat and can trigger false temperature faults.
Inspect the NTC sensor wiring: If you’re comfortable removing the back panel (unplug the machine first), locate the NTC sensor — a small two-wire probe clipped to the exhaust duct or heating element housing. Check the connector is firmly seated and the wires are not scorched or broken. Reseat the connector if loose. If the sensor or wiring looks damaged, order a replacement NTC sensor (search your model number on a UK parts site such as eSpares or 4ourhouse). NTC sensors are straightforward to swap with a screwdriver — no soldering required.
Replace the NTC sensor: If all the above checks pass and the F04 code persists, the sensor itself has most likely failed. A compatible Hoover NTC thermistor costs £10–£25 online. Unplug the machine, swap the sensor, refit the panel, and test.
📞 When to call a professional
If you’ve replaced the NTC sensor and the F04 error still appears, the fault is likely in the main control board — a repair that requires an engineer. Call a Hoover-approved or independent appliance repair engineer and tell them: ‘My Hoover tumble dryer is displaying an F04 error code. I’ve cleaned the filters, checked the condenser, and already replaced the NTC sensor.’ This will save diagnostic time and money.
⚖️ Repair or replace?
An NTC sensor replacement by a professional typically costs £80–£130 all-in (parts and labour). A control board replacement pushes this to £150–£250, which is harder to justify on a machine over 7–8 years old. If your dryer is under 6 years old and the fault is the sensor only, repair is almost always worth it. If it’s older and the board has failed, a new entry-level Hoover condenser dryer starts at around £250–£300 — replacement becomes a serious option.