BoilerFaultCodesVaillant F.67 Fault Code
Also written as F67 — same fault.
The Vaillant F.67 fault code means: your boiler's computer has detected a flame when it shouldn't be there, or is confused by an electrical signal from the burner area.. It appears on 46 Vaillant models in our database.
Technical description: Fault: Electronics/flame - Implausible flame signal
What causes the Vaillant F.67 fault?
This fault occurs when the boiler’s control board detects an electrical signal suggesting a flame is present even though the gas should be turned off. The most common reason is a hardware failure within the main circuit board or moisture and carbon build-up on the sensing electrodes causing a 'ghost' signal. It is essentially a safety conflict where the boiler shuts down because it cannot confirm the burner is actually extinguished.
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.67 fault code
Click a model for the full fault code list and model-specific repair notes.
- Atmomax Repair: £250-£450
- ecoFIT Pure 412 Repair: £180-350
- ecoFIT Pure 418 Repair: £250-450
- ecoFIT Pure 425 Repair: £250-450
- ecoFIT Pure 435 Repair: £250-450
- ecoFIT Pure 825 Repair: £250-450
- ecoFIT Pure 830 Repair: £180-350
- ecoFIT Pure 835 Repair: £250-450
- ecoMAX Repair: £250-£450
- ecoMAX 613 Repair: £280-550
- ecoMAX 618 Repair: £280-550
- ecoMAX 622 Repair: £280-550
- ecoMAX 635 Repair: £280-550
- ecoMAX 824E Repair: £280-550
- ecoMAX 828E Repair: £280-550
- Ecomax Condensing 600/800 series Repair: £300-500
- ecoMAX System 612 Repair: £280-550
- ecoTEC Repair: £280-550
- ecoTEC 65kW Repair: £250-500
- ecoTEC exclusive Repair: £250-£450
- ecoTEC Plus 610 Repair: £250-450
- ecoTEC Plus 615 Repair: £280-£450
- ecoTEC Plus 620 Repair: £280-£450
- ecoTEC Plus 625 Repair: £280-£450
- ecoTEC Plus 630 Repair: £280-£450
- ecoTEC Plus 635 Repair: £280-£450
- ecoTEC Plus 826 Repair: £150-350
- ecoTEC Plus 840 Repair: £280-£450
- ecoTEC Plus 938 Repair: £280-£450
- ecoTEC plus aquaPLUS Repair: £280-550
- ecoTEC Pro Repair: £180-450
- ecoTEC Pro / ecoTEC Plus Repair: £250-£450
- ecoTEC Pro 24 Repair: £180-450
- ecoTEC Pro 28 Repair: £180-450
- ecoTEC Pro 30 Repair: £250-450
- ecoTEC sustain Repair: £280-£450
- Home Combi Repair: £200-450
- Home System Repair: £250-450
- Thermocompact Repair: £220-450
- Turbomax 824/828 Repair: £250-450
- Turbomax Plus Repair: £250-450
- Turbomax Plus 824/828E Repair: £280-450
- Turbomax Plus 828 Repair: £280-£450
- Turbomax Plus 828 E Repair: £280-450
- Turbomax Plus VUW 242E Repair: £280-450
- Turbomax Plus VUW 242EH Repair: £280-450
Source
Vaillant F.67 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