IMM wrote:

"Ian Stirling" wrote in message
...
ski wrote:
Without a doubt it would increase the flow of water through the shower.
I
find that for a mixer shower you need a minimum flow rate of 12.5l

Might an alternative to a boiler upgrade be a heat recovery device
in the shower output?

Best install another combi and join the DHW outlets using check valves and a
shock arrestor downstream of the check valves. Why thrown the combi out?
It works.

And spend money heating water, rather than heating it free...