Low
d.09 on Vaillant ecoFIT Pure 435

Your boiler is simply displaying the target temperature being requested by your external room thermostat or smart control system, rather than indicating a 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 flow set target temperature that is set on the eBUS room thermostat

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

Check your room thermostat to see what temperature it is set toAdjust your thermostat settings if you want the radiators to be hotter or coolerObserve if the display changes when you adjust your heating controls

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d.00View →d.05View →d.40View →

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