HA compatible thermostat

Hardware
1

What are some of the thermostats people around here are using? Currently I have this battery powered dumb thermostat.

Some things to take into account:

  • European system
  • Non-modulating central heating unit (and I’m pretty sure it doesn’t have OpenTherm support)
  • No outlet available where the thermostat should go (i.e. preferably battery powered, but I guess I could re-use the wiring to get power from Live)
  • Can be Zigbee instead of Wifi (already have a bunch of zigbee devices in a mesh)
  • I’m OK with controlling the thing entirely from HA
2

Is it a on/off heating? And do you got space in your central heating. For example to get a loose ESP chip and relay?

Take a read here

3

I was just thinking, perhaps using a Shelly could work as well.
Thermostat > Shelly input > Shelly output > heating system

That way the Shelly can accept or ignore the input from the thermostat and HA can override the thermostat if desired by setting the Shelly in another mode. Wonder if that would work…

4

Alternatively (you’d get no feedback from the stat) but you could just wire them in series, so the shelly switches off at night and if unoccupied otherwise the stat controls the boiler.
I have a couple of danfoss z-wave stats, just used for temperature detection, dedicated boiler switch and all the logic in HA