Low
d.34 on Vaillant ecoFIT Pure 425

Your boiler is displaying the current fan speed for diagnostic purposes rather than an error, but it may indicate an issue with how the fan is communicating with the system.

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

Value for the fan speed

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

Navigate the digital display to your main screenNo action is required as this is a diagnostic statusIf the boiler is not firing, try a single resetMonitor for actual error codes like F.32

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Related fault codes

F.32View →d.33View →

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