Low
S.07 on Glow-worm Ultracom 2 HXI

Your boiler is continuing to run its internal water pump after the heating or hot water has been turned off to safely cool down the heat exchanger.

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 overrun

From this model's manual
Verified against the Glow Worm Ultracom 2 Cxi installation & service manual, page 52.
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 status occurs when the boiler finishes a heating or hot water cycle and needs to dissipate residual heat from the internal components. The pump continues to circulate water briefly to prevent the heat exchanger from overheating or suffering thermal stress once the burner has switched off. It is a programmed safety feature rather than a mechanical failure.

This code is more frequently seen during winter when the heating is used heavily, as the boiler reaches higher temperatures and requires more frequent cooling cycles.

DIY fix possible

Wait for the boiler to complete its cooling cycle, as this code is often a normal operational status rather than a faultCheck that all radiator valves (TRVs) are not fully closed, which can cause heat to build upEnsure the boiler pressure is between 1.0 and 1.5 bar on the front display

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