I am new to this forum and the topic of a “smart home” in general. I am hoping to achieve one thing for now (if not too expensive), and I’d appreciate any help.
I have a “dumb” room thermostat in my apartment that lets me set the temperature manually. I’d love a “smart” room thermostat that allows me to still do this, but then also allows me to program a night setback, as well as to set a specific temperature remotely via an Android app when I am at the office (quite irregularly and not at specific times).
What would be the easiest/cheapest way to realize this? What hardware would I need?
I don’t want any propiertary cloud-based software which led me to Home Assistant. I believe I need a hub (the Home Assistant Green seems to target people like me) and a new room thermostat. I haven’t quite figured out what thermostat would work; I live in Germany so it would have to be available here.
You don’t need a smart thermostat: that is what HA is for.
You need one or more temperature sensors, and the ability to turn your heating on and off from HA.
Then you build all of the smart functions into your HA configuration.
There are lots of simple temperature sensors available. I have built my own using an ESP8266 running ESPHome and using a simple DS18B20 sensor in a 3D-printed case, powered over the wiring that used to connect my dumb thermostat to the heating unit. Although it looks fancy with its OLED screen, it is simply working as a temperature sensor.
My HA setup then uses the Generic Thermostat and a load of logic about when the heating should run — fully controllable from anywhere with the HA app, and automatically switches off when everyone is out:
This has been running completely reliably for more than three years now. Fully local control, doesn’t rely on any cloud connection.
So your first step is to get HA up and running (plenty of hardware options: I run mine in a Docker container on my NAS) then get the ability to control your heating from HA. Everything else follows from that.
What kind of heating and cooling system?
How many heat and cool stages?
What kind of control voltage (120v, 220v or 24v)?
What is you location?
AFAIK, your only, non-cloud based off the shelf option is going to be using the Z-Wave or Zigbee protocols. This will of course require you to purchase more equipment (z-wave or Zigbee stick).
What kind of heating and cooling system?
Hmmm… no cooling system, just some heaters connected to a boiler.
How many heat and cool stages?
I don’t know.
What kind of control voltage (120v, 220v or 24v)?
220v I believe
What is you location?
Germany
AFAIK, your only, non-cloud based off the shelf option is going to be using the Z-Wave or Zigbee protocols. This will of course require you to purchase more equipment (z-wave or Zigbee stick).
Right… any recommendation what thermostat would work for my purpose?
You do that via the HA interface as per my screenshot, which you can do from a phone or a tablet mounted on the wall.
A thermostat is simply a temperature-controlled switch. Typical HA-based solutions split up the temperature measurement (sensor) from the switch (software-driven relay).
If you can work out how your boiler is switched on and off, you could install something like a Shelly One to switch that on and off via HA — just make sure you know what you’re doing if fiddling with 220V mains.
Once set up properly, you’ll probably find you never need to manually set the temperature. I just use the three modes (comfort 19°C, sleep/WFH 17°C and away 16°C) shown, and have tiles set up on my phone to allow me to pre-heat the house in advance if coming home by switching to comfort mode.
I am using something similar for over 3 years now. Using 7 zigbee battery powered temperature sensors with display to see the temperature. Running that as a zone heating. I have underfloor water heating, so generic thermostat was not ideal. Ended up with smart thermostat which works great for me after initial tuning. Switching my heat pump using dry relay contacts.
You only need to make sure your HA does not go down, as this is the logic
