Hi, posted this message on another thread, but didn't quite get any
definitive answers. Please consider:

I am thinking of running both the basin mixer and bath shower/mixer
cold taps off of the mains, whilst still having the hot from the hot
cylinder. (Hot will not be pumped).

My thinking is that I will turn up the thermostat on the hot cylinder
so that it gives much hotter temperature, and then I will only need to
use a small amount of hot flow in the mixer shower, thus utilising
mainly the increased pressure/flow of the cold mains, whilst still
getting a decent temperature.

Now I know it is not the done thing to do this, but before giving your
comments please consider the following:

1. A kithchen sink mixer also usually runs cold off the mains and hot
from the storage cylinder, yet I never hear pple complaining about
'pressure imbalance' for washing up purposes. Why is it any different
for a shower.

2. I usually have an early morning shower, at a time when no-one else
is using any other water supply in the house, so there is no risk of
any sudden temperature/flow change from, say, another tap being used
elsewhere.

3. Because of the usual daily timing of the shower, surely the mains
pressure will also be similar. (I have heard it can vary depending on
how many other pple are using it on the street, or at different times
of the day).

4. If the water is coming through a shower mixer (i.e. pre-mixed), why
would a pressure imbalance between hot and cold have any noticeable
effect?

BTW: I'm not a plumber remember - so please could any
comments/suggestions be of a sort that I can understand and relay to
my plumber in layman's terms.
Cheers