On Mon, 01 Oct 2012 16:39:37 +0100, Roger Mills wrote:

On 01/10/2012 10:00, MarkG wrote:


Can someone elaborate on this? What are my options on how to fix this?
Fit a pressure reducer to the cold feed? What sort of pressure will my
combi hot side have? I always thought it was the same as the mains
pressure when you had a combi....


Chances are that the combi needs to throttle the water going through it
in order to heat it sufficiently. [Otherwise you might have a very high
flow of luke warm water].

What flow rate do you get at (say) the kitchen hot tap? How does this
compare with the rate at the kitchen cold tap. If the cold rate is much
higher than the hot, throttle it so that they are more or less equal.
The shower mixer should then work better.

You seem to have been to posh bathroom supplier, at least by the look of their website.
Would it not be their responsibility to have installed a shower suitable for your
pre-existing boiler?

--
Phil Addison