Vaillant boiler query

[oscarkim1]

I have just had the Ecotec 831 fitted and I have noticed the pump starting to run for about 30 seconds for no apparent reason (the central heating is at the moment not switched on), upon investigation I note that this happens when the Cold tap is turned off. I live in a row of 4 teraced cottages and sometimes this happens when one of my neoghbours turns their tap off. We have a good water supply with no pressure problems so I'm at a loss as to why this is happening. I will revert to the installer of course, but I was hoping someone out there has had similar problems with this otherwise excellent boiler.

[Guy_PGS]

This could very well be the water pre-heat functionality found in vaillant boilers, but could also be air trapped in your pipes. It's worth calling your installation engineer for advice rather than attempting to do a DIY fix. Media URL: http://www.pgs-plumbers.co.uk
Description: London plumbers

[roger]

If you are using pre-existing pipes then check for a capped off branch that's not used and may have air trapped in it , it's known as a "dead leg" i believe. Happened to me years ago when changing from an old tank system to a multipoint type.