Low
d.23 on Vaillant Turbomax Plus 828 E

Your boiler is currently indicating which mode it is set to, rather than reporting a mechanical fault.

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

Summer/winter function (control knob) 1 = winter; 0 = summer

From this model's manual
Verified against the Vaillant Turbomax Plus 824 828e installation & service manual, page 39.
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

Locate the heating control knob on the front panel of the boilerRotate the dial to 1 if you want the heating and hot water to work, or 0 if you only want hot waterObserve the display to confirm the status code disappears once the boiler resumes normal operation

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