Either way, this guide is only really a set of notes to help me remember how I did this and hopefully help someone else who's in a similar situation. I don't pretend to be a plumber/DIY man or anything close, but I refuse to pay a plumber down in London over £500 to 'fix' a shower where a £40/50 service kit did the trick - plus I learnt something along the way!
Anyway, here goes:
This guide assumes you've already turned the water off from your shower. I take no responsibility for any damage you may do to your shower/flat/house in following the below notes!
Firstly you need to find the Mira 723 maintenance guide also available here: http://homepage.ntlworld.com/patrick.beane/mira723maintenance.pdf
Secondly you will need the service parts which I found here: http://www.showerdoc.com/shower-spares/mira/mira-parent-87-mira-723
Following the guide, remove the fascia to be left with something similar to the below:
Remove the four big screws on either corner of the cover and pull to remove:
Remove the temperature control (coil looping around the main cartridge) to be left with (note, if the whole cartridge comes out in one go, don't worry!):
At this point remove the white/beige deflector and then pull the who cartridge straight out of the enclosure (may take a bit of a wiggle and a good pull!):
Note the locating pin on the centre bottom of the enclosure - you'll need to know about this when putting back together again.
Dismantle the cartridge to be left with the below components:
After cleaning and o-rings removed:
Note the bottom of the three is the flow control. Mine was ceased together with lime-scale, so required a vice and the correct spanner to undo it (I tried every known limescale remover/dissolver in B&Q and made absolutely no difference. To unscrew, hold the 'chamfered end with the spanner notches' still and turn knob end anti-clockwise, which should reveal the below:
As per service manual, clean up the components, grease, replace o-rings, washers and put back together again!
Knob should turn with a bit more than a fingertips force and should turn four or five full turns before being full on.
Hope that's helped someone out there!
