Low
d.77 on Vaillant ecoFIT Pure 425

Your boiler is struggling to efficiently heat your hot water cylinder, likely due to a poor connection or an incorrect settings configuration.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Max. cylinder reheating

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.10View →F.11View →

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