Low
d.34 on Vaillant Home System

Your boiler is currently showing its internal fan speed information rather than a fault, which usually indicates the system is performing a diagnostic check or starting up.

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: Current value in rpm. Fan speed=Display value x 100

From this model's manual
Verified against the Vaillant Home System installation & service manual.
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 required; this is an information code rather than a fault.Observe the boiler to see if it moves to a standard operation code (e.g., S.4).If the display is stuck on this menu, press the 'back' or 'info' button to return to the main display.

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Related fault codes

F.32View →d.33View →F.22View →

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