I've got a related question.
We're installing a new shower and combi boiler system:
I've been told by the guy who's installing the boiler that we should
definitely go for a manual separate hot/cold shower as these are far
more reliable, particularly in hard water areas (london).
Is he right? I don't like the idea of fiddling with the controls all
the time and having the water go hot and cold.

Any advice much appreciated.

n