Shower handle - Maker? Disassemble?

[Johncooper314]

Moved into new apartment in high-rise building. Shower has a thermostatic control valve that I suspect needs a new cartridge, because hot and cold seem to be mixing when the shower is not running. This heats up the cold water in other pipes, all of which feed off of one larger chase.

Control has single pole with two handles - one handle controls flow rate, the other handle controls temperature.

Cannot find name of manufacturer and cannot find set screws or other obvious way of disassembly.
Four pix of the handle attached. Google search with the pics provides a different answer for manufacturer with each of the four pix (Lol).

Would anyone recognize the maker / manufacturer? And / or have information on how to disassemble and replace cartridge.

Thanks very much.

 

[CENTRALFL]

The top handle looks to have a cover or sorts (or some seam). Have you tried to see if that pops off? I didn't have luck with Google or chapgpt...

 

[Sponsor]

 

[Johncooper314]

That is my best guess, too.
I have a plumber coming tomorrow morning. The pipes are shared with the unit next to me, so I wasn’t able to try all the things I wanted to try. When the plumber is here, I will be happy to watch him Him do whatever. I hope to learn a lot.
Thanks.I

 

[TJRAD]

Should say Brizo under the handles:
if it does then I believe this is your model.
Good luck.

 

[Johncooper314]

Thanks very much. The plumber came this morning, and he did see "Brizo", which I had missed. He was able to replace the cartridge, with on from a plumbing supply company in town. All good. I might get a new O-ring for the outermost plate - that got dinged up as it was pried off. He thought this was similar or identical to a Delta unit.
Again - thanks!

 

[Johncooper314]

More information to finish the story and thank TJRAD. I did need to order the temperature knob assembly. When prying off the front plate, the plumber did not know about the set screw holding the outermost (frontmost) plate onto the knob, and the threaded piece was broken off. Until I realized that and ordered a new one, the place did not attach properly onto the handle.
Fyi, the cartridge was $500, and the labor was $500. In retrospect, I could have done it myself (with a new cartridge). The handle even has shutoff valves for hot and cold water, so I would not have had to close the valves in the wall.