Glowworm cx30i gas boiler?

I thought I'd be alittle less sarcastic than my co-contributor.

You have, I assumed, checked the manual. The one I looked at I found at http://www.glow-worm.co.uk/glow-worm/cxi-range-157150.pdf

I saw this:

11.9 Pump Exercise Program
After a power cut or every 24 hours in holiday mode the three way valve will switch and the pump will run to prevent the components from sticking. This will also occur during normal operating if there is no domestic or central heating demand for more than 24 hours.

Thefre is also a pre-heat function that may be running.

Having a 30CXi myself, I can confirm these do run occasionally up for a few moments, even when there is no demand.

XXX
November 2016

Sounds like it is doing its job. Leave it alone!

No faulty temp sensor or pressure just the end user as usual.
November 2016