Thought I’d share how I hooked my Wyze thermostat to a 2-wire millivolt wall heater, integrated with Google home and has been working perfectly since install (5 days).
When installing, the app said my system isn’t compatible. But you can ignore and proceed.
I bought a 24v adaptor to power the thermostat. Here is how I wired it.
Rh and W1 are from my heater.
Rc and C come from the 24v adaptor.