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S.23 on Vaillant ecoTEC Plus 615

Your boiler is currently preparing the burner to provide hot water, which is a normal part of its operation.

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

Hotwaterhandlingmode:Burnerignition

What causes this fault?

This code appears when the boiler detects a demand for hot water and is physically firing up the burner to meet that request. It is a normal part of the start-up sequence and indicates that the internal components are working correctly to heat your water. You will typically see this briefly on the display every time you turn on a hot tap or shower.

DIY fix possible

This fault may be fixable without an engineer. Check your manual first.

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Related fault codes

S.20View →S.21View →S.24View →

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