Low
d.10 on Vaillant ecoFIT Pure 435

Your boiler is displaying a status message to show that the internal pump responsible for circulating heat is currently active.

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

Status of the internal pump in the heating circuit

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

No action is required as this is a status code, not a faultCheck that your room thermostat is calling for heatWait for the boiler to complete its current heating cycle

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