"John Aston" wrote in message
.. .
(Sorry - Posted this reply using my wife's newsgroup reader by mistake...)

Andy Hall wrote in message
...
On Wed, 6 Oct 2004 00:40:02 +0100, "John Aston"
wrote:

snip

Is there any way around this problem? A pump and hydraulic accumulator
sounds expensive. Due to a loft conversion, there is not any convenient
space for a cistern, although I'm thinking that I may have to create
some...

Don't forget that there are tanks available in different shapes and
sizes from Polytank and that one can always link more than one
together if it helps with the nature of the space available.

About the only other option is to look into having a larger diameter
service pipe installed from the road main into the house. THis can
be disruptive and not inexpensive of course.


Hi, Andy.

Unfortunately, I have already replaced the service pipe with a new 32mm
diameter pipe. Cambridge Water tell me that they can't do anything about
the
flow/pressure "because the supply is fed directly from a reservoir".

Space in my loft is very limited, but I do have basement space so I could
get an accumulator.

GAH make a "Dualstream" accumulator but you have to buy their rebadged
Ariston unvented hot water cylinder with it. I don't know anything about
the
quality of Ariston.

For a 300 litre accumulator and 300 litre cylinder the list price is £2112
(less 40% from a distributor I'm told!). The 300 litre accumulator is 5'2"
high and almost 2' diameter so it takes up a lot of room.

I suppose that I'll have to compare the Dualstream cost with a "cistern
and
pump" solution and take a view on it.

I assume you haven't bought any equipment yet. In your situation which I
assume you have 1 bath and two showers, and I would go:

1. Combi boiler (to do the two showers only)
2. A "combination" cylinder with quick recovery coil. (cold tank and hot
cylinder all in one space saving unit). This operates at low pressure
http://www.rcmgroup.co.uk/specialized.htm RCM will make a large cold tank
section for you. They will ake the hot and cold section sizes to order.

The CH side of the combi acts as a normal system boiler heating the cylinder
and CH. The cylinder does the bath and therest of the house to give good
fillups. The water side of the combi only does high pressure showers.
Something like an Alpha CB50, W-B Greenstar high flow condensing combi would
do. The W-B Greenstar 40kW model can deliver 16 litres/min and you need to
add cold to the showers, so a decent shower had if two on at the same time.
This approach is cost effective and no power shower pump used.

Another approach is a "combinatiuon" cylinder witha quick recovery coil
serving all hot outlets and cold for showers using a conventional power
shower pump for then showers and a condesning system boiler. Use a Torbeck
ball valve in the cold section and 22mm cold mains directly to it to give
repaid fills ups. The Torbeck is either on or off.

Will you really have the bath filling and a shower on at the same time? A
relative has had a single shower power shower pump serving two showers for
10 years. Not once has two showers been on at the same time.