Low
S.7 on Vaillant ecoMAX 618

Your boiler is temporarily keeping the internal pump running to safely cool down the heat exchanger after a period of heating.

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

Pump over run (heating operation)

From this model's manual
Verified against the Vaillant Ecomax 613 installation & service manual, page 45.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This occurs when the boiler has finished a cycle and needs to dissipate residual heat to prevent the internal components from overheating. The pump continues to circulate water through the system after the flame has gone out to ensure the heat exchanger cools down safely. It is a standard safety feature and usually indicates the system is working exactly as it should.

This status is more frequently observed during winter when the boiler is working harder and running for longer periods to heat the home.

DIY fix possible

Check that all radiator valves are not turned off at onceEnsure the bypass valve (if visible) is openWait for the boiler to finish its cooling cycle and return to normal operation

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