I've got the Platinum XL850 (smilar to your model) , and it definitely joins the network as a secondary hub.
Unfortunately as far as I could determine from the documentation, it doesn't expose any of the Thermostat functions through Zwave. It wants to be a controller an get you to use the Nexia service.
I hate the thing. It's sometimes interesting though, as it "sees" (discovers) devices that are relayed through it, and offers up drivers for them (if you upgrade).
It sees one of my Locks, although I don't actually know which one.
I've also found that it loses it's temperature reading mind sometimes and gets "stuck" at a measured temperature until you decide it's too cold, and overrride the heat setting. At this point, it suddenly "discovers" the temp is 3 degrees lower than it had previously measured, and you're soon being cooked as it rises to the new set temp.
How do you get it to join as a secondary hub? I deregistered from Nexia and found it, but when I re-registered it with Nexia it got hung up on registering the z-wave repeater. I had to reset the z-wave settings to get it to connect to Nexia.
I think when you do the setup, it gives you the option of joining an existing network, (with dire warnings), as I recall it's under Advanced in the Zwave menu. It may be the "Learn" option under that menu.
I went ahead and set up Nexia, free level, and then joined it to Hubitat in the usual way, with discover. I think I must have been in the "Learn" mode described above. Hubitat found it as a "device", and I've presently got it running a generic thermostat driver, but it doesn't actually do anything, or pass any info, so I could have left it as a "device".
The nexia still occasionally identifies "new" devices. I suspect when I run a Zwave repair, sometimes things get routed through the thermostat as a repeater/secondary hub, and Nexia finds them then. Doesn't seem to cause any problems though...although it's possible the thing is interfering with successfully re-joining my front door lock.
Hmmm...I'll have to think about that...sorry, rambling...
S.
@scottgu3 just wondering if you had any f/u on your Trane xl850 thermostat.
We love our variable speed compressor system because it will run at very low levels to keep humidity down here in Florida summers. HOWEVER we hate that you basically can't use ANY other thermostat other than this one to control it. Any other smart thermostat that isn't communicating type will revert the system back to 2-stage which loses those benefits.
Are you still stuck with basically no integration or function with the xl850? It would be really nice to be able to use Hubitat to switch to vacation / away mode easily with this system.
Yeah, still stuck. The first one went wonky, so had to replace it. Flat out the Nexia thermostats want to be your home hub, and while they join as a secondary controller, they don't seem to make available any of the Thermostat data or control information. Useless.
Unfortunately, that leaves me with no way forward. As far as I can determine there are no z-wave or Zigbee thermostats that handle multistage heat pumps and variable speed compressor AC systems.
I wonder what adding a second thermostat in parallel would do. If you leave it off (not heating or cooling) would it report what the furnace was doing. Just musing.
I have been using IFTTT to automate my XL850. With them moving to a paid model, I want to move away from IFTTT if I can. I understand that the thermostat does not expose any of it's functions through zwave, but I'm wondering if there could be another way to integrate it.
When you log into mynexia.com you can setup an automation and use the trigger "third party automations". The only 3rd party integration listed is IFTTT. So I can use IFTTT and a presence sensor to say if the sensor is not presence, set the thermostat to 78/65. But each one takes up an IFTTT applet. I'd need another applet to say "If the sensor is present, run schedule".
I've got another one to lower the temp for 2 hours. It's for nap time for the kids. So we can say "okay google, it's nap time." and IFTTT will set the thermostat and after 2 hours will run schedule.".
The biggest problem is that everything you want to trigger will take up an applet spot on IFTTT.