In article ,
Broadback wrote:
My daughter has a combi boiler and is looking for a shower,owing to
space it will be in the bath. She has decided she would prefer one to
run off the combi rather than electric to get higher pressure. Having a
tight budget she would like to forgo a thermostatic one. This made me
wonder what is the disadvantage of a shower off the bath taps is as
against a dedicated mixer shower. All advice and views most welcome.

My experience of a combined bath tap & shower unit has been good... BUT
only in situations where both taps are fed from the same pressure
source. Eg. both from a loft tank (the hot via a traditional cylinder fed
from the same tank) or both from the mains (but watch out for restrictors
on the input to the Combi)

The down-side is that if someone opens a tap or flushes the loo then
it can have a rather sudden and drastic effect on temperature and
flow rate...

One house I lived in had mains cold water and tanked hot - it was
almost impossible to regulate the temperature to the shower unless we
ran the cold tap in the sink full blast to take some of the flow away
from the bath, and even then it was still very touch & go about
regulating it.

Good luck..

Gordon