On Fri, 3 Sep 2004 22:30:27 +0100, "Andrew Beck"
wrote:

You are right, this is static pressure.

The boiler spec says it requires a pressure of 0.3 bar for minimum flow rate
(2.7 l/min)

Interesting I have found the following quote about water flow rate on my
water company's web site

" A simple check: provided the cold tap in your kitchen (whilst running at
full bore) can almost fill a 2 gallon bucket within about 1min, your flow
and pressure is satisfactory. "
(http://www.threevalleyswater.co.uk/h...pressure.shtml)

Which is about what I'm getting.

They would say that.

This works out to slightly over 9 litres per minute.

The statutory minimum for water companies to meet is.. you'll never
guess.... 9 litres per minute,

Of course it isn't satisfactory - a more reasonable figure is twice
that. The trouble is that in some places the water companies would
have to spend a fortune to meet 20 lpm.


My problem is an unbalanced flow, all cold and no hot.

What I'm looking for is a balanced flow i.e. the cold water flow is no more
than 50 % of the total water flow.

You could try a simple solution of introducing a restricting valve on
the cold path to force more flow through the hot path; or perhaps a
pressure equalising valve. The trouble is that you haven't got much
to work with.

The best solution would be to look into getting the supply from the
street upgraded.

Failing that, another solution would be to install a conventional hot
water cylinder with a storage tank in the roof and fill that from the
mains. Heat this cylinder from the heating circuit by adding a
divertor valve and cylinder thermostat. Use the stored hot water for
baths and showers and the combi for less critical applicatiions like
the kitchen.



..andy

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