I have a shower control unit made by a Italian company
called bossini, it's square in shape and has a big square which switches between shower head and shower hose, then a smaller square which does the temperature. Just yesterday the temperature adjustment does not seem to work and it is now mainly a cold shower, does anyone know where to get bossini spares from or if I can use a universal thermostat replacement cartridge, I have a vid on YouTube http://youtu.be/l1ms4KCJpLA. Can anyone advise or help

Dharms, January 2013

Your vid does not show much except not my style.
I would suggest block plug hole. Turn off water. And then take it apart, could just need a clean out, depends on water hardness etc, but by taking it apart, you will find your answer, even take bits to a local plumber merchants or go down to B+Q or something. Might just need a new seal or something. Do not think it is something very serious. BUT by taking it apart you will find out. From what you say you cannot use it, so nothing to loose, except small bits falling out, which is why I said block the plug hole.

SD, January 2013