alt Hacker NewsWireless thermostats are really common in the UK. I don't know about elsewhere. I'm interested how they pair (like Bluetooth) with the boiler.
Basically, the thermostat is in a living area and you set the temperature(s) to what you want, it senses them, and then talks to the boiler (in my case in the roof-space) to heat up (or not, via radio) the water in the radiators to satisfy that. It's a feedback loop.
I'm maybe just a fuddy duddy but relying on wireless tech for critical systems unnecessarily seems like asking for trouble. Running wires to a boiler isn't generally that complicated and it's just one less point of failure.