Low
d.01 on Vaillant Turbomax 824/828

Your boiler is currently running its internal pump to move excess heat away from the system, which is a normal part of the cooling process after the heating has been turned off.

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

Water pump over run

From this model's manual
Verified against the Vaillant Turbomax 824 828 installation & service manual, page 39.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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