Home/Boiler Fault Codes/Vaillant F29
VAILLANT FAULT CODE
Vaillant F29
The boiler ignited successfully but the flame then went out during operation, and subsequent attempts to reignite failed. Common causes include a faulty flame sensor or an intermittent gas supply.
WHAT F29 TYPICALLY INDICATES
The boiler ignited successfully but the flame then went out during operation, and subsequent attempts to reignite failed. Common causes include a faulty flame sensor or an intermittent gas supply.
WHAT TO DO
There is no safe homeowner check for a flame-loss fault. 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.
Seeing Vaillant F29 on your boiler?
Tell us the code and your postcode. A fully Gas Safe registered engineer will diagnose the actual cause before quoting a fix.
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