I want to be able to control my thermostat from my phone, so I’m looking for recommendations for one that meets the following:
- Works with no network access (as in, I can access it but it can’t access anywhere else, enforced via VLAN on my firewall)
- Lets me control my single apartment thermostat (temperature, heat/cool, maybe programming but it’s okay if I have to do that on the unit directly)
- Not hundreds of dollars
- No microphone
Any thoughts? Really just want something simple.
Edit: I have no other smart home devices right now, if that matters.
A ZigBee local control thermostat OTH4000-ZB. No cloud services needed.
You can turn off the internet access at almost all Tuya devices by making use of the local tuya HACS add on in home assistant. Maybe that’s helpful for your research
Recently I went through some pain with this myself. Had a full Heatmiser setup with wireless receivers in every room and 2 manifold controllers for our underfloor heating on two floors.
The devices ate batteries like nothing I’ve seen before and regularly dropped off the network and didn’t send call to heat signals properly, so I decided to switch out the thermostats for cheap ZigBee temperature sensors.
I then ordered a relay board from AliExpress with a baked in esp8266 cheap and flashed esphome onto it. These replaced my manifold controllers
After trial and error, I now have my heating system run by esphome and home assistant. It has been faultless! Will probably reinstall the Heatmiser kit if I sold the house though
I use the Sensi ST55 with the Home Assistant HomeKit integration. I got it from my utility company for $1 as part of an Earth Day promotion, but they sell it for $25 now. You might be able to find it pretty cheap where you are.
Honeywell T6 ZWave is great. Simple, classic touchscreen controls, and local radio control that just works. No AI funny business either. Mine is hooked up to Home Assistant via a Zooz USB dongle.
I’ve greatly enjoyed ZWave things in general compared to the wild west of ZigBee and WiFi devices. They’re sometimes more pricey, but they pretty much just work.
I’m pretty sure sensi thermostats, when controlled by home assistant, do what you want. I haven’t confirmed they don’t still try to phone home, but that could be dealt with by some firewall rules. Other thermostats that support homekit should also work.
Look into open therm gateway with something like a dumb Honeywell Round modulating thermostat unless your thermostat already supports open therm.
I got two Honeywell T9s with remote sensors for $150 each from my utility company. I’m happy with them.
Do you control your thermostat via ir remote?
If so, an esp32 or esp8266 running esphome and an ir led connected to a pin might be a solution.
Would cost like 3 dollars in parts from AliExpress, and you could connect it to home assistant or node red for more control or automation.
You could also add a temp sensor like for example ds18b20, which are also pretty cheap, if you want to be able to read temperature remotely or automate based on temp
Nope, I just walk up to it and push buttons if I need to make changes.
What’s the thermostat controlling? How is it wired up? I replaced mine with ram esphome with a temp sensor and a relay that bridges the pins when it wants to turn on. Mine is connected to home assistant but i think you can use esphome devices stand alone.
This is probably not a useful answer, but it’s the level of knowledge that I have: it controls the heating and cooling, and it just gets pushed into the holder on the wall.


