Medium
d.44 on Vaillant Ecomax Condensing 600/800 series

Your boiler is displaying a real-time measurement of the flame signal, which is a diagnostic check rather than an active error, but if it is persisting, it indicates the system is struggling to confirm the burner has lit correctly.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

Actual ionisation–current value

Engineer required

This fault requires 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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