Low
d.34 on Vaillant ecoFIT Pure 435

Your boiler is displaying a technical information readout regarding the current fan speed rather than an actual fault code.

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

Value for the fan speed

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

Press the 'Back' or 'Menu' button to exit the diagnostic modeTurn the boiler off and back on again at the fused spur switchIf the code persists, ensure you are not accidentally holding down the 'plus' or 'minus' buttons

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