Low
d.25 on Vaillant ecoFIT Pure 435

Your boiler is currently being told by your thermostat to heat your hot water tank or maintain a pilot of pre-warmed water.

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 requirement to reheat the cylinder or for the hot water warm start from the eBUS thermostat

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

Check your thermostat or programmer settings to ensure hot water is scheduled correctlyAdjust your hot water temperature target if the demand is occurring too frequentlyWait for the boiler to finish the heating cycle as this is a status indicator rather than a fault

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