Home/Boiler Fault Codes/Vaillant F27
VAILLANT FAULT CODE
Vaillant F27
A flame-simulation safety lockout — the monitoring electrode has reported an incorrect flame signal, and the boiler shuts down immediately as a precaution. Recurring F27, F61 and F62 codes together can point to a failing main circuit board.
WHAT F27 TYPICALLY INDICATES
A flame-simulation safety lockout — the monitoring electrode has reported an incorrect flame signal, and the boiler shuts down immediately as a precaution. Recurring F27, F61 and F62 codes together can point to a failing main circuit board.
WHAT TO DO
This is an immediate safety lockout and should never be repeatedly reset without investigation. This is not a DIY fix — it requires a Gas Safe registered engineer to diagnose and repair safely.
A NOTE ON GAS SAFE REGISTRATION
Any work on the gas side of a boiler in the UK legally requires a Gas Safe registered engineer, it isn't optional. Our engineers are fully Gas Safe registered, and you're always welcome to ask to see ID on the day. This page is general information about what a fault code typically indicates; it is not a substitute for an engineer diagnosing your specific boiler.
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