Low
P.12 on Vaillant ecoTEC plus Aquaplus

Your boiler is undergoing a standard automatic self-test procedure during startup and is temporarily pausing to check its internal systems.

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

Not applicable - for GB

Engineer required

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

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Related fault codes

S.00View →

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