Help needed re a bath hot/cold mixer tap with a hand held shower (switched
by lever at base of outlet).
The instructions state that that water regs require non return valves along
with isolators on the h&c feeds. No problem with that.
The instructions then continue (not under "regs") "to obtain optimal
results......be checked"
a) hot & cold water supplies must be balanced
b) The cold feed should come from the cold water tank and bold not the
mains
c) words to the effect at least 2m head of pressure

Hoping I've supplied all relevant info the question is:
Is the requirement at b) normal - I think its stone age
Would I get these requirements from Pegler, Bristan etc. (haven't checked if
they do anything similar)

Thanks

PeterK