Low
S.19 on Vaillant ecoTEC exclusive

Your boiler is currently running a brief internal testing sequence to check hot water settings and will return to normal operation by itself.

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

DHW mode: Measuring programme

Engineer required

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

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