High
d.69 on Vaillant ecoFIT Pure 435

Your boiler is struggling to light its flame and is failing on the second try, which usually indicates an issue with the fuel supply or the ignition components.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Number of unsuccessful ignitions at 2nd attempt

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

F.28View →F.29View →

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