Low Information
S.23 on Vaillant ecoTEC Pro 24

Your boiler is simply going through its normal process of lighting the burner to provide you with hot water.

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: Ignition. The ignition for domestic hot water mode is activated.

What causes this fault?

This is a normal status code rather than a fault, occurring every time you turn on a hot tap. It indicates that the boiler's internal computer has successfully detected a request for hot water and is now physically sparking the burner to heat it. Once the flame is established and the water reaches the set temperature, this code will typically transition to another status.

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.24View →S.02View →

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