Low
d.23 on Vaillant Turbomax Plus VUW 242E

This code is not actually an error; it is a status message showing that your boiler is currently set to 'Summer' mode, meaning it will only provide hot water and not central heating.

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 of your boiler panelTurn the dial clockwise to the 'Winter' position (indicated by a radiator icon)Observe if the heating system begins to activate

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