Decentralized heating

Hello everyone
I was wondering if it is possible to make your own system with openHAB such as Netatmo thermostat with thermostatic valves or the Honeywell Evohome with valves. By that I mean that you have a central thermostat but can control it with thermostatic valve(s) (each valve is then basically a thermostat). For example, if your living room is warm but your bathroom is not, your bathroom will still be heated. If this is possible, what would I need for this? And is this possible with a Nest thermostat. Since I have this now. If not possible with Nest no problem. I’m open to buy a new thermostat.

(I’m in Belgium so I use a EU Nest thermostat.)

Thanks in advance. Kind regards Jan

I know there are Z-Wave solutions (valves and thermostats) that could do that and be controlled by OH.

Google has closed the Nest API so using OH would likely now be a challenge. They want to force you to use Google Assistant so they get all your data.

Thanks for the info. Any recommendations for a Z-Wave thermostat(s) that are able to do this ?

Where in the world are you located? Z-Wave options are region-specific.

I’m in the EU, Belgium. My heating system works on oil and I use radiators.

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I am in the US.
I tagged this thread for Z-Wave so a couple of our experienced EU users should be along.

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Spirit, Aeon or Fibaro. All supported.

I prefer the Spirit and Aeon over the Fibaro.

Early Fibaro firmware was a bit suspect and I am not convinced they have fixed all issues. Check their forum for details.

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So the I looked up the Spirit and the Aeon they look great.

But what thermostat do I need ? or control unit that can turn my heating boiler on/off.

Thanks for the help.

Don’t forget the Devolo / Danfoss LC-13 :wink:
Mine are working pretty well.

You would need a Z-Wave controller, likely a USB stick to talk to openHAB too.

It depends on your boiler setup and how you want to run your house.

At the very simple end

is designed for the purpose of a simple switch for a boiler/valves. Wiring depends on your boiler hot water and heating system.

All of the valves have built in thermostats so do not need a room stat but you can use an external temperature sensor if you want to on the Spirit, Fibaro and Aeon.

There is a thread on here for the Spirit/Aeon and any zwave temperature sensor or temperature sensor that works with openHAB can be used. Fibaro is a bluetooth unit paired directly.

The Devolo / Danfoss LC-13 only have built in only.

If you want to switch the boiler pump and boiler off when valves are off the Spirit and Aeon report how open the valve is so you can turn off the pump when all valves are closed.

One thing to be careful of with the selection is that while the Devolo / Danfoss LC-13 are excellent devices they are traditional sleeping devices so will not respond to commands until they wake. The Fibaro and Devolo / Danfoss LC-13 do not tell you how open or closed they are.

The Fibaro, Spirit and AEON are FLiRS whcih means they regularly wake so respond within a short time to changes sent to them.

Then as Bruce says you need a zwave controller. Do consider that non mains powered zwave devices can not repeat the signal so to get coverage in a large area you may need some powered devices to repeat the signal from your controller and back.

Okay this explains a lot to me. and is very helpful.

So what I need is:

  • openHAB off course.(running on whatever device, probably gonna be a Raspberry Pi)
  • Z-wave USB (I suppose a SmartThings Hub will work as well ?)
  • A switch to turn my boiler on and off ( something like a SECURE SSR303 Z-Wave+ actuator 1 channel)
  • And The Thermostatic valves

My kitchen and living room are one big place with 5 radiators maybe its best to use a thermostat or sensor in this room ? I’m still renovating so I could put it in a separate water circulation loop and use 1 valve.

So if I’m right the heating schedule is in openHAB ?
Is there an option to see your consumption ?
And an ECO option like nest has ? (probably need to add a sensor ?)

Sorry this is new for me but I’m very interested. In the future I would like to add my Qbus domotic system and lots of other stuff :slight_smile:.
And thanks again for making me understand it.

That would give you extra work if you also wanted to use openHAB. You could potentially use just the smartthungs but that is a different story.

openHAB is compatible with a usb zwave stick.

Yes, but it requires a lot of programming. I’ve made a thermostat-like rule in OpenHAB, so I can control every room separately (it’s still in development) and also with an ECO mode.
You can see your consumption if you have a smart meter (you can measure your gas usage).

This is what I use for my heating:

  • OpenHAB 2.5
  • Aeotec Z-wave stick gen5
  • Fibaro Relay switch (FGS-221) (for boiler controler and under the floor heating valve control)
  • Eurotronic Spirit Zwave valves (for radiator control)
  • Heiman Smart temperature sensor (for measuring room temperature)
  • Smart Virtual Thermostat (beta version)

For every radiator you need the Eurotronic Spirit, for every room (can be with multiple radiators) a temperature sensor.

Good luck!

I use Honeywell Evohome system with Evohome binding. No issues so far. It runs with latest 2.5.3 as well. Evohome binding 2.0

If you can get your thermostat, valves, and room-specific temperature sensors connected to openHAB, then you can absolutely do something like what you’re wanting. I have it working in my house with Keen Home Smart Vents, but the vents are just a number item that I set between 0 and 100 percent, so a valve could work similarly too. (I do not recommend these vents, in case anybody is considering a similar system. Happy to elaborate if somebody wants to know, but it’s a bit off topic for this thread.)

Based on my experience setting it up, I suggest this: Get a basic thermostat that you can set a schedule on but doesn’t have much more smarts. You want to the smarts to be in openHAB. I have a ecobee thermostat, but it turns out I have to work around a lot of ecobee’s smarts because I want to do it a different way. So, say you have a z-wave thermostat that lets you set a schedule for every day of the week. You use that thermostat to control the overall target temperature of the house. Then you need a temperature sensor in each room that you’d want to control. Any sensor will do. I use some of the ecobee sensors because I already had them, but prefer Sonoff TH10/16 with Temperature sensors with Tasmota installed on them because they are really cheap and reliable.

The general idea is that the thermostat sets the target level for the whole house. It manages whether the HVAC is in heat or cool mode. Certain rooms may get hotter or cooler, or you may have specific preferences (I like my office cooler than other areas). You can configure that within limits. If the heat is on and my office is warmer than I’d prefer, there’s nothing I can do other than close the vents so more warm air doesn’t get in. If the cool is on, I can keep the office vent open and close other rooms’ vents as they cool down so cool air keeps blowing in the office. By default, rooms use the thermostat setpoint as their target, but this can be customized for each room. It’s not exactly the same as different thermostats in every room, but it can be tweaked to work pretty well. Other people may have different ideas of how to do this type of thing, but my setup has worked fairly well for me overall.

You can see my setup for controlling temperatures per room here:
It’s coded using the openHAB rules language, which makes it less elegant than I’d prefer, but it was the best option available when I wrote it and it works for me.

I would not recommend using a SmartThings hub as this requires jumping through hoops to make it work. My vents use Zigbee, so I had to use SmartThings when I set it up. I’m using an MQTT intermediary to pass messages between the two, and it is not completely reliable. If you have Zwave devices, using a Zwave stick on your openHAB server will be much more reliable.

Our Zigbee binding doesn’t work?

It probably does now. When I was initially working on the system it was 3 or 4 years. If I recall, there wasn’t even a zigbee binding at the time.