"Doctor Evil" wrote in message
...

":::Jerry::::" wrote in message
news.net...

"Doctor Evil" wrote in message
...

snip

He is wrong. Divide and rule. Try two combi's. one doing one
shower,
one
doing the other. Combine the outlets for the baths to fill them
quickly,
using non-return valves and a shock arrestor on the bath side on
the
non-return valves.

Have one combi do upstairs heating and one do downstairs. Simple
and
cheap
and effective. Have each combi have its own gas supply right
back
to the
gas meter.

Check the mains water pressure and flow. Replace the mains stop
cock with a
full-bore stop cock irrespective, and have dedicated 22mm cold
supplies to
the combi's from the stop cock. Take the cold supply for each
shower off
the combi supply just before the combi. Any pressure
fluctuations
on that
line will be equal on both cold and hot at the shower.

Combi's are cheap.

But the work to install all of the above isn't.....

Combi's are one box solutions, the simplest and easiest method of
installation. This place is to have 6 people showering in the
morning. Say
the average shower is 100 litres of hot water. That is a 600 litres
of
water requiring storage. A hell of a lot. Even 500 litres is a
hell of a
lot, and expensive to provide storage for, with maybe the floor
requiring
strengthening. Only combi's with their infinitely continuous
supply of hot
water can provide the solution to this problem economically. Two
combi's.
One for each shower, join the outlets for the baths. Everyone
satisfied, no
digruntled tenants, no running out of hot water, and also backup.
If one
combi goes down, one will work giving a shower. So they will have
to wait
longer for a shower for a few days, but at least there will be hot
water and
heat in the house.


What happens if either the gas or power fail, result no hot water
unlike with a storage tank, OK there is only a limited supply but
every one will be able to wash using flannel, soap and a bowl....

I also suspect that after the cost of running two water supplies from
the company valve, two gas supplies from the meter together with all
the extra CH/HW pipes one could have installed a large boiler and
storage tank.