Low
d.58 on Vaillant ecoFIT Pure 425

Your boiler is notifying you that it is currently using extra heat to prevent your solar heating system from getting too cold.

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

Solar circuit reheating

From this model's manual
Verified against the Vaillant Ecofit Pure 830 installation & service manual, page 31.
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 solar controller to ensure it is powered onMonitor the boiler as this message usually disappears automatically once temperatures adjustNo action is typically required if you have hot water and heating

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