Title says it all really.
Recently moved into a new property that already has Hive (I'm told it's a 2nd gen... the thermostat part has model "SLT3") but the previous occupant took the "hub" with her... so basically we don't use it via the Hive "mobile app" anyway (as we can't without that "hub"). But obviously we've got the receiver (next to the boiler) and the thermostat/display thing - which talk to each other with zigbee... which is what got me thinking.
So basically wondering if I can integrate with that directly, without needing Hive / British Gas / or any kind of subscription / Internet connection / Cloud API. Additionally if we upgraded the boiler and that came with a new Hive... any gotchas to watch out for to do the same?
The HA integrations page suggests cloud polling only?