Medium
d.28 on Vaillant ecoFIT pure

Your boiler is struggling to talk to an internal control switch that handles extra features like pumps or external fans.

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

Function of relay 2 (multi-functional module)

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.27View →F.70View →d.27View →

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