In an earlier contribution to this discussion,
Fred wrote:


Sorry I haven't replied to this thread for a while, I shall try to do
so today or tomorrow. In the meantime can I ask one quick question:

Do I need 28mm pipe for central heating/hot water if the system is
pumped? Is it that 28mm is only for gravity fed systems? If there is a
pump in place, does 28mm offer any advantage over 22mm?


28mm (or 1" Imperial in the 'old' days) is certainly needed for gravity
circulation in order to minimise flow resistance - 'cos convection doesn't
generate much pressure.

22mm is usually sufficient for pumped systems unless you have a very large
or very leaky house with a correspondingly large boiler. There's no
particular merit in using 28mm pipe unless you really need to. On the other
hand, if you're converting a gravity system to pumped, and some conveniently
located 28mm pipe is already installed, there's no point in *not* using it.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!