Low
S.23 on Vaillant Turbomax Plus 828

Your boiler is currently preparing itself for a warm start to ensure you have hot water quickly when you turn the tap on.

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

Ignition sequence (warm start)

From this model's manual
Verified against the Vaillant Turbomax Plus 824 828e installation & service manual, page 38.
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 is required as this is a normal status code, not a fault.If you wish to stop the boiler from pre-heating, you can turn off the comfort/warm start function using the control dial.Ensure your thermostat is set to the desired temperature if you have no heating.

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