A: http://www.showerdoc.com/MIRA-935-01-Mira-Service-Pack-Temp-915-(comp-B)-935-01
You could try the above service pack, but it does sound like the radatherm assembly is faulty.
http://www.showerdoc.com/MIRA-412-06-Mira-Radatherm-Assembly--components-Identified-H-Exp-And-Built-in-412-06
These cartridges are very difficult to take apart and depending on its age and state you may have to bite the bullet and replace the whole unit if you are unable to get it apart.
http://www.showerdoc.com/MIRA-412-01-Mira-Cartridge-Assembly-Radatherm-412-01
Answered 88 days ago | Barrie