Hello Paweł P
I got mine yesterday and chose bht-002 GC for our gas boiler.
It was switched via a relais with its own phase so I choosed the one with potential free relais.
My recent experiences on these thermostates: If you by them now they will mostly have newer firmware which isnt flashable ota via tuyaConvert!
But wired flashing works fine 🙂 👍
As you are using actuators you will need bht-002 GA to power these.
Have a look at the description pictures