On 27 Oct, 10:09, Onetap wrote:
On 26 Oct, 19:38, jgharston wrote:

Grrr. This is why I prefer proper stored hot water systems...

My shower has a mira Discovery thermostatic mixer, one of
these:http://goo.gl/0n7g

Try as I might I can't actually get the hot water to be hot.
With the temperature control turned all the way to "hot" it

It's a TMV and comes factory set to a (low) maximum temperature (43
deg or so typically) which is low enough not to cause scalding to
elderly or disabled people if installed in a care home or such. The
idea is the makers don't get sued when a numpty plumber causes
scalding to someone's granny. You can alter the maximum temperature,
usually involves taking knobs off and such. See manufacturer's
installation instructions.

No, ignore that. You've done it.

probably unequal pressures or a defective cartridge.