Low
S.20 on Vaillant ecoTEC Pro 30

Your boiler is simply letting you know that it is currently preparing to provide hot water to your taps or shower.

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 demand

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.21View →S.22View →S.23View →

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