High
d.69 on Vaillant ecoTEC Plus 635

Your boiler has failed to light the flame after two attempts and is currently tracking how many times this has happened.

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: Current value

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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