Yeah, high end installations have been using them for years. You won’t find them in the big-box stores. I looked into all that when I redid my showers and decided to just go with Delta “Monitor” mixers. It worked pretty well with the old tank heater and it’s indistinguishable from a thermostatic now that I have an on-demand water heater. As a bonus, the Monitor valve is interchangeable with a regular mixer valve in case I’m broke when it fails and need to buy a cheap mixer valve.
I think the Monitor brand uses wax like you described in a comment but they don’t call them thermostatic, probably to differentiate them from their actual bimetal products.
Yeah, high end installations have been using them for years. You won’t find them in the big-box stores. I looked into all that when I redid my showers and decided to just go with Delta “Monitor” mixers. It worked pretty well with the old tank heater and it’s indistinguishable from a thermostatic now that I have an on-demand water heater. As a bonus, the Monitor valve is interchangeable with a regular mixer valve in case I’m broke when it fails and need to buy a cheap mixer valve.
I think the Monitor brand uses wax like you described in a comment but they don’t call them thermostatic, probably to differentiate them from their actual bimetal products.