Hello all,

Just though I'd call in here to run this one past the more experienced...

I currently have a gravity fed hot water system. I'm about to build a small
extension and will replace the current boiler while doing so. I have
pondered for a while the idea of a mains pressure hot water system but am
really concerned about the lack of pressure at the upstairs shower. I
currently have a pressure pump installed and the shower is brilliant. I also
like the idea of a combi simply because of the fact that I'll never "run
out" of hot water.

Anyway, after reading loads of stuff on the web I have concluded (maybe
wrongly!!) that I should have a combi to feed everything but the showers and
retain the current hot water cylinder and pump just for the showers. I'd
obviously have to somehow plumb in the system to heat the water cylinder and
that will no doubt necessitate the use of motorised valves etc. I realise
that I'll still need to keep the loft tanks but don't mind that. I'll also
have two hot water supplies in case one fails and stored water in the loft
is always handy should there be a mains supply problem.

So, am I thinking right? and is there any where on the web where I can
source a plumbing & wiring diagram for this type of set up? I can plumb and
wire but haven't a clue where to start on this. I'll obviously need the
boiler to be on call for the central heating and the hot water and these
need to be independent.

Any other idea's appreciated too.