Anyone know if it's possible to buy replacement cartridges in Chiang Mai, & where? Don't want to buy a complete shower fitting.

I can get one from China through AliExpress, but I would prefer to buy here.

What shower unit does that fit in?

Teka. I tried the service centre here several years ago for a replacement (the knob you turn to control temp was broken) & they could only offer me a new shower!

The photo is from AliExpress. Large range for sale, seem like standard dimensions.

I am sure you may have done these . soak in mild descaling fluid ? Also drop in near boiling water remove then cold water a few times, this can free them up as well, if this works you should see it open and close, replace o rings good luck

I am sure you may have done these . soak in mild descaling fluid ? Also drop in near boiling water remove then cold water a few times, this can free them up as well, if this works you should see it open and close, replace o rings good luck

Descaling is not the issue. I have a broken off temperature control knob, Need a new cartridge.