Low
d.00 on Vaillant ecoFIT Pure 435

This is a settings menu adjustment that controls the maximum heat output of your boiler rather than a mechanical breakdown.

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

Heating maximum output

From this model's manual
Verified against the Vaillant Ecofit Pure 830 installation & service manual, page 29.
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

Navigate to the installer level menu by pressing 'Menu' and 'Back' together.Select diagnostic code d.00.Adjust the kilowatt (kW) setting to match your home's heating requirements and save.

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