Low
S.012 on Vaillant ecoTEC plus Combi

This is a normal operational status message indicating your boiler is preparing to provide hot water, not a fault code.

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.

What the manual says

Manufacturer manual

The domestic hot water draw-off is active and the heating pump is in prerun mode.

From this model's manual
Verified against the Vaillant Ecotec Plus installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

No action required, as this is a normal status message and not a boiler fault.

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Related fault codes

S.010View →S.011View →

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