I’m looking to get a “smart” thermostat. I don’t want it to call back to any server and it would preferably be powered via poe. I’m wondering if anyone has any experience with these thermostats. Particularly the honeywell or zwave thermostats.
I might just end up building my own but I thought I’d see what’s out there first
You and me both. I’ve been looking for one that is locally controllable without needed to interface to a ‘cloud’ infrastructure. I’ve seen a couple of Z-Wave ones, but I am unsure if they are still in production. I’ve only found them on some discount sites.
So… I too would love to find either a Wifi, wired, or zwave thermostat that can be controlled locally (does not need to interact with an outside service).
Tasmota on a Sonoff Zigbee WiFi bridge, Sonoff temperature sensors for your zones and some ESP8266 controlled relays running ESPHome at the HVAC unit(s). Tie it all together with Home Assistant if you have family, of Node-red if you’re hardcore.
User interface is an old phone/tablet glued to a wall
When internet access is gone, many smart thermostats just degrade into dumb/timer thermostats.
On the frontend you have some ui to set the temperature and a temp sensor, on the backend you have relays to turn heating/cooling on/off.
They typically can’t really do fine grained control of your heating cooling system (usually the units have their own internal thermostats that might be dangerous to mess with).
What kind of heating (or is it cooling system) do you have? Underfloor/radiator/hvac … is it a heatpump, electric, gas… do you need per room temperature setting (recommend).
E.g. I currently have gas powered condensing boiler and radiators . Nest controls the boiler overall, and the living room temperature. Tuya makes “smart” zigbee connected thermostatic radiator valve heads that can turn the radiator valve less/more often that are controllable via home assistant. I have temperature sensors in each room feeding temperature into home assistant - controlled via phone.
No they’re not integrated (there’s some APIs for that now, but I haven’t investigated them) for my situation - overall it’s ok.
Nest thermostat makes decisions to turn heating on off based on temperature where it is. I’ve put it in the living room that just so happens to be the most poorly insulated room in the house (on the account of stupid subfloor insulation+fireplace+vent mandated by fireplace…).
Without home assistant, the hot radiator water will heat the living room as well as other rooms - other rooms will be 3-4⁰C warmer - the colder the day the bigger the difference.
With home assistant, the radiators in warmer rooms will close when the room reaches target temperature, and more warm water will flow through the living room radiator until it reaches target temperature too.
Theoretically I could rip out nest and wire a diy $2 wifi connected relay, or even a sonos sonoff to “call for heat” line, then home assistant can decide to turn the heating on without nest… I haven’t done that yet.
It’s basically what they call the S-Plan … think like Python’s any built-in, as long as any thermostat wants heat, the gas boiler will turn on, internally it’ll monitor inlet-outlet temperatures and flow rates and adjust the burn to have constant outlet water temp, so if more thermostats use more heat it’ll adjust the rate of flow of gas to compensate for more heating needed.