Chris J Dixon wrote in message . ..

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?

The mixer will be trying to achieve the set temperature by
opening and closing apertures for the two flows, If they are at
significantly different pressures it will be difficult to limit
the higher pressure flow to admit enough of the low pressure one.

Chris

Right, so the if higher pressure will be the cold, that stops me
getting scalded, which is what I'm most worried about.

If there is a concern that not enough of the lower pressure flow (in
this case the hot) will be admitted surely this will be sorted
(admittedly with a bit of initial fine tuning) by setting a high
enough temperature for the hot on the cylinder thermostat.

So far, this is sounding like a good idea......Would someone please
provide a convincing argument as to WHY I DEFINITELY should NOT try
this !

It sounds like a win win situation, (Especially as under my current
arrangement (cold fed from storage tank in loft) the hot cylinder
thermostat is set to its minimum setting, and even then I only need to
set the mixer flow very slightly to hot to get a comfortable
temperature).