Sonas temperature regulator not working

[Astra]

Hello,

I have this Sonas shower valve system: https://www.sonasbathrooms.com/en/sh...wer-valve.html

The temperature regulator is not working, it turns, but it's stiff, and it's not changing the temperature of the water which currently comes hotter than the deepest lake in hell.

Does anyone know how I can take it apart to have a look at what might be wrong with it?

Thank you.

 

[ShaunCorbs]

I would see if you can get spare parts first eg the cartridge for a start

normally the handles are held on with grub screws these can be under little covers, under handles eg you remove the handle first etc