Low
d.31 on Vaillant ecoFIT Pure 835

Your boiler is notifying you of its current automatic filling system setting rather than indicating a breakdown or safety failure.

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

Automatic filling device (0=Manual, 1=Semi-automatic, 2=Automatic)

From this model's manual
Verified against the Vaillant Ecofit Pure 830 installation & service manual, page 30.
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

Identify if you want the boiler to top itself up or if you prefer to do it manuallyAccess the installer level menu (code 96) to adjust the setting if desiredPress the 'Back' or 'Menu' button to clear the status display

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