Low
d.25 on Vaillant ecoFIT Pure 412

Your boiler is simply communicating with your hot water tank or controls to let them know it is ready to heat water when needed.

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

Status of the requirement to reheat the cylinder or for the hot water warm start from the eBUS thermostat

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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