Low
d.11 on Vaillant Home System

Your boiler is simply indicating whether its internal pump is currently running or resting while distributing heat through 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

Status of the heating circuit's shunt pump: off/on

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

This fault may be fixable without an engineer. Check your manual first.

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Related fault codes

d.10View →d.13View →

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