BoilerFaultCodesVaillant F.10 Fault Code
Also written as F10 — same fault.
The Vaillant F.10 fault code means: your boiler has stopped working because it has detected an electrical fault with the internal sensor that monitors the temperature of the water leaving the unit.. It appears on 47 Vaillant models in our database.
Technical description: Short circuit – flow–NTC (< 130 °C), NTC– plug shorted to casing, NTC defective
What causes the Vaillant F.10 fault?
This fault occurs when the electrical signal from the sensor that monitors the outgoing water temperature is interrupted, usually due to a physical failure inside the component. The most common reason is that moisture or heat stress over time has damaged the sensor's internal wiring, causing it to send an incorrect 'short-circuit' signal to the main control board. If the sensor cannot safely report the temperature, the boiler will shut down as a safety precaution.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Vaillant models that show the F.10 fault code
Click a model for the full fault code list and model-specific repair notes.
- Atmomax Repair: £90-180
- ecoFIT Pure 412 Repair: £120-220
- ecoFIT Pure 418 Repair: £120-220
- ecoFIT Pure 425 Repair: £120-220
- ecoFIT Pure 435 Repair: £120-220
- ecoFIT Pure 825 Repair: £120-220
- ecoFIT Pure 830 Repair: £120-200
- ecoFIT Pure 835 Repair: £120-220
- ecoMAX Repair: £90-160
- ecoMAX 613 Repair: £120-£190
- ecoMAX 618 Repair: £120-£190
- ecoMAX 622 Repair: £120-£190
- ecoMAX 635 Repair: £120-£190
- ecoMAX 824E Repair: £120-£190
- ecoMAX 828E Repair: £120-£190
- Ecomax Condensing 600/800 series Repair: £120-220
- ecoMAX Pro 28E Repair: £120-220
- ecoMAX System 612 Repair: £120-£190
- ecoTEC Repair: £90-180
- ecoTEC 65kW Repair: £150-250
- ecoTEC exclusive Repair: £90-180
- ecoTEC Plus 610 Repair: £120-220
- ecoTEC Plus 615 Repair: £90-160
- ecoTEC Plus 620 Repair: £90-160
- ecoTEC Plus 625 Repair: £90-160
- ecoTEC Plus 630 Repair: £90-160
- ecoTEC Plus 635 Repair: £90-160
- ecoTEC Plus 826 Repair: £120-200
- ecoTEC Plus 840 Repair: £90-160
- ecoTEC Plus 938 Repair: £90-160
- ecoTEC plus aquaPLUS Repair: £95-170
- ecoTEC Pro Repair: £100-£180
- ecoTEC Pro / ecoTEC Plus Repair: £100-£180
- ecoTEC Pro 24 Repair: £100-£180
- ecoTEC Pro 28 Repair: £100-£180
- ecoTEC Pro 30 Repair: £120-220
- ecoTEC sustain Repair: £90-160
- Home Combi Repair: £120-200
- Home System Repair: £90-170
- Thermocompact Repair: £120-£220
- Turbomax 824/828 Repair: £120-200
- Turbomax Plus Repair: £120-220
- Turbomax Plus 824/828E Repair: £90-180
- Turbomax Plus 828 Repair: £90-160
- Turbomax Plus 828 E Repair: £90-180
- Turbomax Plus VUW 242E Repair: £90-180
- Turbomax Plus VUW 242EH Repair: £90-180
Source
Vaillant F.10 fault code information on this page is sourced and cross-checked against the official Vaillant service / installation manuals for each affected model.
- Vaillant ecoFIT Pure 412 manual (PDF)
- Vaillant ecoFIT Pure 835 manual (PDF)
- Vaillant ecoMAX manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026