Low
d.40 on Vaillant ecoFIT Pure 425

Your boiler is displaying the current water temperature being sent to your radiators, which is a normal status message rather than an error fault.

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 temperature

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

No action is required as this is a status code, not a faultIf the temperature seems too low, you can adjust the central heating dial to increase warmthMonitor the display to see if the code changes to a fault code starting with 'F'

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