Low
d.23 on Vaillant ecoTEC plus aquaPLUS

Your boiler is currently set to summer mode, which means it will provide hot water but your central heating is switched off.

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)

From this model's manual
Verified against the Vaillant Ecotec Plus Aquaplus installation & service manual.
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 left-hand control knob on the boiler fascia with the radiator icon.Turn the knob clockwise to your desired heating temperature setting.The 'd.23' status should change as the boiler switches back to winter mode.

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