On 2007-10-01 19:18:37 +0100, Olly said:

Well just tested flow rate and its 20 litres a min. Would this be
sufficient for a mains presured hot water cylinder such as megaflo or
would I require the pressure of the water as well.

That isn't how it works. Pressure is not the same as flow.

20lpm would be just about enough for one shower with single, simple
shower head - i.e. not a drencher or ody jets etc.



Does this mean that
in theory a shower would produce about 40 l/min if both hot and cold
are fully open?

No it doesn't. 20lpm is the *total* coming into the house. Some
will go to the shower as cold water, while some will go via the
cylinder, but it can never exceed 20lpm.

The only way that you can make a difference to that is via some means
of storage. This is why roof tanks can deliver large volumes of water.