cassman Wrote:
I am considering a style change to the bathroom which will include the
changing of all taps and the shower mixer valve.

I have seen the style I am after but am unsure of the procedure for
replacing the mixer valve. Taking it that the gap between the hot and
cold entry pipes are the same on the new valve as the old one, is it
simply a task to isolate and undo the supply pipes and fit the new
valve or am I still going to have to make holes in the walls to gain
access to the pipework?
hi, isolate both supplies, saying that connection center to center is
the same,disconnect old valve,if theres enough play in the pipework cut
the copper, remove nut and ring,fit new valve, if pipework is solid try
cutting the O ring off only, be carefull not to cut into copper,remove
o ring and nut, replace valve,turn water back on check connections,
then operate shower valve ( remove shower head to flush system to
eliminate any debris)

Watch out for the required length of pipe poking out the wall my be
different for different valves. Changing my crappy house builder fitted
Triton valve for a Mira Excel required me to lengthen the pipe poking out
the wall. Luckily Osma Gold (so I have now been told) push fit fittings were
used in the wall and I was able to extract the pipe section from the right
angle bend whilst in the wall and replace with a longer piece with very
little effort. Make sure you tie/tape the pipe in the wall to prevent you
dropping it, in my case in the wall cavity, when you have removed the pipe
from the right angle.