Tumble Dryer
F01
The F01 error code on a Bosch tumble dryer points to a fault with the appliance’s NTC temperature sensor — the component responsible for monitoring heat inside the drum. It’s one of the more common fault codes on Bosch heat pump and condenser dryer models, and while it can sound alarming, it’s often caused by something straightforward like a blocked condenser or a faulty sensor that’s relatively affordable to replace. In this article, you’ll learn exactly what triggers the F01 code, which fixes you can safely try yourself, and when it’s time to call in a professional appliance engineer.
What does this error mean?
The F01 error code on a Bosch tumble dryer indicates that the control board has detected an abnormal reading — or no reading at all — from the NTC (Negative Temperature Coefficient) thermistor. This is a small temperature-sensing probe that continuously feeds temperature data back to the dryer’s main electronic control board during a cycle. When the board sees a reading that falls outside the expected range (either too high, too low, or a completely open circuit suggesting the sensor has failed), it triggers the F01 fault and shuts the dryer down as a safety precaution. In plain terms: your dryer’s ‘thermometer’ has either malfunctioned or is reporting temperatures that suggest something is dangerously wrong with the heating system. The machine is protecting itself — and your home — by stopping.
Est. repair cost
DIY NTC sensor replacement: £10–£25 for the part. Professional repair (sensor replacement including call-out and labour): £80–£150. PCB replacement by an engineer: £180–£280 all in.
🔍 Likely causes
🛠️ Step-by-step fix
1. Power cycle the dryer: Switch the dryer off at the wall, leave it unplugged for at least 5 minutes, then plug it back in and run a short cycle. This clears any temporary electronic glitches that may have triggered a false F01 reading. No tools needed.
2. Clean the lint filter thoroughly: Remove the lint filter (usually located in the door seal rim) and clean off all fluff and debris under a running tap if necessary. A blocked filter restricts airflow and can cause the sensor to log abnormal temperature spikes. Allow it to dry fully before reinserting.
3. Clean the condenser unit: On condenser and heat pump models, locate the condenser behind the bottom kick panel (consult your model’s user manual). Remove it carefully, rinse it under a slow-running cold tap to flush out dust and fluff, and leave it to dry completely before refitting. Bosch recommends doing this every 1–3 months depending on usage.
4. Clean the heat exchanger (heat pump models only): On Bosch heat pump dryers, there is a secondary heat exchanger behind the condenser. Use a soft brush or the brush attachment of a vacuum cleaner to gently remove any fluff build-up. Do not use water on this component. Check your model’s manual to confirm access procedure.
5. Check the dryer is properly levelled: Use a spirit level on top of the machine and adjust the feet until the appliance is completely stable and level. Excessive vibration from an unlevel machine can shake loose the NTC sensor’s wiring connector over time.
6. Inspect the NTC sensor connector (ONLY if you are comfortable doing so safely): After unplugging the machine from the mains, remove the back panel (usually held by 4–6 Torx or Phillips screws). Locate the NTC sensor — a small probe typically clipped near the heating duct or drum outlet — and check that the wiring plug is firmly seated. Reseat it gently if it appears loose. WARNING: Only attempt this if you are confident working around appliance components. If in doubt, call a professional.
7. Test the NTC sensor with a multimeter (advanced DIY): With the machine unplugged, disconnect the NTC sensor and use a multimeter set to resistance (Ohms) to test the sensor. At room temperature (around 20°C), a healthy Bosch NTC thermistor typically reads approximately 5,000–6,500 Ohms. A reading of zero, infinity, or wildly outside this range confirms the sensor has failed and needs replacing. Replacement NTC sensors for Bosch dryers are widely available from UK parts suppliers such as eSpares or 4ourhouse and typically cost £10–£25.
8. Replace the NTC sensor if confirmed faulty: Purchase the correct NTC sensor for your specific Bosch model (check your model number on the rating plate inside the door or on the rear of the machine). Fit the new sensor in the same position as the old one, reconnect the wiring plug securely, replace the back panel, and run a test cycle. Video guides for your specific model are often available on YouTube.
9. If the error persists after all of the above: Do not continue to run the dryer. The fault may lie with the main control board (PCB), which is not a safe or cost-effective DIY repair for most homeowners. At this point, contact a qualified appliance engineer.
📞 When to call a professional
Stop DIY attempts and call a professional appliance engineer if: the F01 error returns immediately after a power cycle and you’ve confirmed the lint filter and condenser are clean; the NTC sensor tests within the correct resistance range but the error persists (suggesting a PCB fault); you’re not comfortable removing the back panel or working inside the appliance; or the dryer is showing any signs of burning smells, visible scorch marks, or unusual noises alongside the error code. When you call, tell the engineer: ‘My Bosch tumble dryer is displaying an F01 error code. I’ve cleaned the lint filter and condenser, power-cycled the machine, and the fault has not cleared.’ This gives them a head start and may reduce your call-out time. Look for an engineer who is a member of the Domestic Appliance Service Association (DASA) or who can provide evidence of experience with Bosch appliances specifically.
⚖️ Repair or replace?
If your Bosch tumble dryer is under 5 years old, repair is almost always the right call. Bosch is a premium brand with excellent parts availability in the UK, and a straightforward NTC sensor replacement — even done professionally — is likely to cost far less than a new machine. If the fault turns out to be a failed PCB on a dryer that is 7–10 years old or more, the maths starts to shift: a new main control board can cost £80–£150 for the part alone, and with engineer labour on top you could be looking at £180–£280 all in. At that point, consider that a solid new Bosch condenser dryer starts at around £350–£500, and a heat pump model from £500–£800. As a general rule: if the repair cost exceeds 50% of the price of a comparable new appliance, replacement becomes the more sensible long-term investment — particularly if your current machine is over 8 years old. If your dryer is under warranty (Bosch offers a standard 2-year warranty and extended cover is available), contact Bosch Home Appliances UK directly on 0344 892 8979 before spending any money on repairs.