Am I right in saying that with a combination boiler with no header tank,
with direct connection to the mains water, that is is inappropriate to use a
booster pump?

I am planning to redo the bathroom, to include a separate shower unit. I was
planning to use a thermostatic controlled shower unit to blend hot and cold
feeds.

Presently we have a shower over the bath, with a combined tap/shower without
any temperature regulation.
This is very hard to adjust and both the hot and cold flows seem to be quite
restricted. However, the old tap/shower unit may well have got a bit of
scale or gunge, but I was expecting more vigorous flow, and suspected that
the low pressure might be detrimental with a new shower too.

I just did a pressure test, and have 32 psi dead ended pressure.
This was on the ground floor, so 3 metres higher (bathroom upstairs) it will
be ~5 psi lower.

That seems a bit lower than I expected, but I have no real data to compare
it with.

Checking the installation instructions from a shower plucked at random from
'tinterweb, it seems that it would be ok with pressures of 1 bar, or even
lower if the flow restrictors are removed.

Am I worrying needlessly? Am I missing something? Does anyone have any
advice for me please?



Cheers Alan