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 45 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.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Avoid the next call-out bill
A cover plan would handle faults like F.67: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Vaillant models that show the F.67 fault code
Click a model for the full fault code list and model-specific repair notes.
- ecoFIT Pure 412 Repair: £180-350
- ecoFIT Pure 418 Repair: £250-450
- ecoFIT Pure 425 Repair: £250-450
- ecoFIT Pure 435 Repair: £150-£400
- ecoFIT pure 612 Repair: £200-450
- ecoFIT pure 615 Repair: £200-450
- ecoFIT pure 618 Repair: £200-450
- ecoFIT pure 630 Repair: £200-450
- ecoFIT Pure 825 Repair: £250-450
- ecoFIT Pure 830 Repair: £180-350
- ecoFIT Pure 835 Repair: £250-450
- ecoFIT sustain 415 Repair: £250-500
- ecoFIT sustain 418 Repair: £250-500
- ecoFIT sustain 430 Repair: £250-500
- ecoFIT sustain 615 Repair: £200-450
- ecoFIT sustain 618 Repair: £200-450
- ecoFIT sustain 630 Repair: £200-450
- ecoFIT sustain 825 Repair: £200-450
- ecoFIT sustain 830 Repair: £200-450
- ecoFIT sustain 835 Repair: £200-450
- 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 824/2 E Repair: £280-550
- ecoMAX 828/2 E Repair: £280-550
- ecoMAX 835 E Repair: £280-550
- Ecomax Condensing 600/800 series Repair: £300-500
- ecoTEC exclusive Repair: £250-£450
- ecoTEC plus Repair: £280-550
- ecoTEC plus VU GB 656/4-5 A Repair: £250-500
- ecoTEC pro Repair: £180-450
- ecoTEC sustain Repair: £280-£450
- Home Combi 25 Repair: £200-450
- Home Combi 30 Repair: £200-450
- Home Combi 35 Repair: £200-450
- Home Regular 12
- 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 425 manual (PDF)
- Vaillant ecoFIT Pure 435 manual (PDF)
- Vaillant ecoFIT pure 630 manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026