Mixer shower expertise please!

[DIYspanner]

The temperature control valve seems to be seized and I want to remove it.
This is the valve set in the wall.
Does the chrome sleeve have to be removed first?

This is the on/off control.

 

[plumblddy]

Dreadful installation, RIP it all out and start again would be the best way to go.

 

[DIYspanner]

Dreadful installation, RIP it all out and start again would be the best way to go.

I've already ripped an Aqualisa digital shower out and replaced it with a Mira exposed bar shower, albeit the Mira is now on to a third exchange unit due to a leak from inside the bar on each.

Back to my question, does the chrome sleeve have to be removed before the valve can be removed?

 

[opps]

In my limited experience, the chrome sleeve needs to be removed first.

Has someone tiled over tiles?

 

[plumblddy]

I've already ripped an Aqualisa digital shower out and replaced it with a Mira exposed bar shower, albeit the Mira is now on to a third exchange unit due to a leak from inside the bar on each.

Back to my question, does the chrome sleeve have to be removed before the valve can be removed?

Usually yes but it's been grouted in!

 

[DIYspanner]

Job done!

I used a small drill bit to remove the grout from around the chrome sleeve which then screwed off.
A hex grub screw holds the valve in place so. With the grub removed, the valve assembly pulls out.

It a brass valve and easily dismantles for cleaning with limescale spray. I applied silicon grease to all the o rings when reassembling.

What's baffling me is the position the valve needs to be for the control knob assembly to be refitted. Should the valve fully left, fully right of mid point when the control is at 12 o clock?

I'm not going to seal in around the chrome sleeve. I intend to refit the cover plate and apply silicon around the plate edge unless anyone can advise me better.

Thanks!

 

[DIYspanner]

I managed to get some information on the thermostat valve.

Its a matter of adjusting the valve to get a water temp of 40° C then fit the control.