"mp" wrote in message
...
Hi all

I'm about to install a power shower (I can imagine it's been covered
umpteen
times) but despite doing a previous search about my problem I've seen no
answers/solutions.

The problem is that the cold water feed to the shower mixer comes direct
from the loft water tank (normal) DOWN through to the mixer, whereas the
hot
water comes from the airing cupboard through the floorboards and UP to the
mixer.

So my problem is getting the pipes close enough for the pump to connect
to.
I can't use a post-mixer pump due to wall cavity being so thin (barrats
house!).

Solution - I was thinking of feeding the cold water DOWN to the airing
cupboard and then feed it UP back in the loft to rejoin where cut into it.
The problem I see with this is extra work for the pump, ineffective
pressure
(15mm pipes not 22mm) or the need for a negative feed switch (which then
raises the question about the hot water feed being positive).

In an ideal world I'd feed the cold water down to the airing cupboard and
then relay through the floorboards (same as the hot water feed), but the
floorboards are larges T&G and very tough to get access to.

Thanks for any thoughts.

MRJP



HI There,

The simplest method for your existing installation would be to do as you
suggest.
Put the pump in the airing cupboard. Route the existing shower cold feed
from the tank down to the airing cupboard in 22m. Take the pumped hot outlet
to the existing shower hot feed, and take the pumped cold up into the loft
to the original cold feed.

Although the up and over run on the cold feed is not ideal, I woulnd't
expect this to cause problems with air locks as it's on the pumped output
side of the run.

You could do as Big Wallop suggests and take the cold feed from the input
feed to the hot water tank. Some manufacturers give this method as an
option. Yes the ideal method is a dedicated feed from the cold water tank
and Surrey/Essex flanges from the hot water cylinder but you won't get shot
if you don't do it that way.

I have scanned a section of a manual for a power shower showing three
options for connection www.geocities/wjp_gof/shower.doc

Method 2 shows a cold feed taken from the supply to the hot water tank. You
may experience variations in shower temp when other outlets are being used.

The reality of this depends on your cold water installation. If all the
other cold water appliances in the house are on high pressure mains, then
you won't have a problem.
I ran a power shower for years plumbed in this way and it worked fine.

Regards Bill

ps Method 3 illustrates the dialogue between Big Wallop and Set Square.