Low
d.02 on Vaillant ecoFIT Pure 425

Your boiler is taking a temporary break to prevent itself from turning on and off too frequently, which helps save energy and protect its internal components.

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

Burner anti-cycling time in heating mode

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

Wait 15-30 minutes for the countdown to end naturallyCheck that your room thermostats are turned up higher than the current room temperatureEnsure at least one or two radiators have their valves fully open to allow heat to circulate

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