Low Information
S.27 on Vaillant ecoMAX System 612

Your boiler is briefly running its internal pump to circulate water and manage heat after it has been turned off, which is a normal operating state rather than a breakdown.

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.

Technical description

Pump over run (warm start)

What causes this fault?

This status occurs when the boiler has finished heating your home or water and needs to dissipate the remaining heat from the internal heat exchanger. The pump continues to run for a short period to circulate water and prevent the internal components from getting too hot while the burner is off. It is a protective feature designed to prolong the life of your boiler and is not a sign of a mechanical failure.

DIY fix possible

Check if your heating or hot water is still working as normalWait a few minutes for the status code to change automaticallyEnsure your radiator valves are open to help heat dissipate

Find a Gas Safe engineer
Search the official register →

Related fault codes

Related guides you might find useful