It's an air separator and that pipework is shite :lol similar here
http://www.toolstation.com/shop/Heating/...708/p75473
see if a magnet will stick to it, if it does its a pretty good indication that the system is shitted up. If you are fitting a combi it will be cut out anyway but, make sure you have the system well flushed and fit a system filter.
http://www.toolstation.com/shop/Heating/...708/p75473
see if a magnet will stick to it, if it does its a pretty good indication that the system is shitted up. If you are fitting a combi it will be cut out anyway but, make sure you have the system well flushed and fit a system filter.