Low
d.21 on Vaillant ecoTEC plus System

This code is simply an information message telling you whether your boiler's 'fast hot water' feature is currently turned on or off, rather than signaling a fault.

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 warm start for hot water: off=Function deactivated, on=Function activated and available

DIY fix possible

Locate the 'warm start' or 'comfort' button on your boiler's control panelPress the button to toggle the setting between 'on' and 'off' based on your preferenceNote that no further action is required as this is a status screen and not an error

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