Large Underfloor Heating Setup - Homatic, multiple RaspberryMatic


I’m looking into doing a large setup for controlling the underfloor heating of several houses.
The houses are all connected with LAN already.
Is it possible to connect multiple RaspberryMatic to OpenHAB and then control the Homatic actors across them all? So that a sensor on the first RaspberryMatic can control a actor on a second RaspberryMatic?
The LANGateways from Homematic don’t seem to be able to talk to the Homatic IP Unterfloor Heading stuff and also you can only connect 3 LANGatesways. In the long run I will need more like 10 Stations.

Or any other idea for a large setup like this?

Thank you for your help

Yes … I deal with 2 piVCCU … Basement & Apartment :slight_smile:

directly linking Actors from CCU 1 to CCU 2 doesn’t work…

Logic from Openhab works perfectly…

Depends on where you put the control layer. If you code that inside OH then you could use any OH compatible technology as binary switches to open/close valves and for temperature sensors.
But HVAC systems should be designed to always work autonomously i.e. independent of any RaspberryMatic or OH server, internal network, Internet access, cloud service, whatever, and eQ-3 clearly is not an expert on HVAC. I doubt you will find HVAC craftsmen (which you will still need) to accept and maintain that setup.

So basically you are saying that OpenHAB and HomeMatic is not “good enough” to control a heating system?
What else would you recommend then? My idea is to later integrate more and more components into this system. So also sensors for power consumption of each floor in the fuse box, controlling of the pumps for the heating system, etc

No, I’m running a system similar to that myself (without that Homematic crap though).
But I’m saying that you need a fallback to work without OH and HM. Even more so if you don’t build it for yourself but for others. And in that context you need to think of how maintenance will work - will you be able to do that all by yourself ? Even when you’re on vacation ? If no, you need some 3rd party to do it for you, and I doubt you’ll find anyone willing to.

Which sensors and actors for underfloor heating would you recommend other then the “Homematic crap”?
We are building that for ours self, it is a large self administrated community living project.
How would you plan such a setup in term of the fallback? Or do we need the big expensive Siemens stuff after all?

You can use any OH-controlled temperature sensor. Its placement is way more important than the technology.
If you plan for a wired or wireless smart home switching system beyond HVAC such as KNX or ZWave, you can use devices from a wide range of vendors.
You can also get DS18B20 sensors for ~1€ each that you can connect to/control either through 1-wire gateway such as a Pokeys57E, to GPIOs on a RPi or as an addon to actuators such as Qubino Z-Wave . I myself am using Fibaro FGMS multisensors for motion and lux sensing, that’s including temperature.

The issue with Homematic isn’t with the sensors or thermostats, it’s because that is proprietary technology. No vendors to choose from, absolutely no support from the vendor, no 3rd party in the know (with KNX you’ll at least find a couple of electricians that know to handle it).

I will look into the wired stuff as well as we have a lot of old cables from analog telephone and a Nurse call Bus system.
Do you know of any other actors for the underfloor heating then the HomeMatic ones? They seem to be able do also open a bit rather then just open/close state.

But why?
What is the different between a heating system like Uponor, Danfoss Link, Wavin, Roth and Salus etc… And then a Rpi running openhab??

The only differences, (in my opinion), the Rpi with opehab is more difficult to setup, and is a 100% DIY system. But when it´s up running and optimized, I simply cant see the differences.
Rpi with openhab is like building your own Wavin etc system.

Which fallback option do a Wavin, Roth, Danfoss Link users etc have??

I simply dont get it. It sounds like you´re questioning openhab stability?

I’d install a “classic” electromechanical system in the first place to provide the basic-most and safety-related features
(Frostschutz, Anti-Legionellen-Durchheizung, Notabschaltung bei Strom- oder Druckverlust usw.)
Most modern boiler controllers have the required control features builtin. You do NOT need to build a complete classic system to have all the features (and cost). It does not need sensors nor actuators nor mixers nor any sort of temperature control etc. but it should be able to operate the pumps (unless you design the system to have them running 24x7).
I’d use NC or NO valves depending on what you think is the larger risk (freezing pipes+cold rooms or flooding+waste of energy) in case the upper control layer (OH or its devices) fails.

I’d then put my OH controlled actuators/sensors in parallel (in terms of electrics/mechanics) to that so they can a) see and b) override the basic system.
For example, I’ve put an FGS-223 between my boiler/controller and pumps.
That’s a general purpose dual OH-controlled zwave actuator intended to use e.g. with lights. It has an input that you would usually attach the light switch to, this is where I’ve put the controller’s output into which would otherwise go straight to the pump. So the pump switches ON/OFF when either the boiler control sends the command via wire or when I send this via OH/ZWave myself.

Unlike radiators, underfloor heating systems are rather inertial and modern ones steadily run at minimum temperatures throughout most of the day. You simply don’t need the capability to partially open valves, that’s a waste of money and higher risk of components to fail.
That is regularly misunderstood by HVAC newbies (and even many self-proclaimed “experts”). Just get thermoactive actuators in 230VAC (or 24VDC) and put them on OH-switchable binary channels (which you can use any OH supported technology for).

But DON’T underestimate the amount of efforts and ‘classic’ electro-mechanical engineering that was and still needs to be put into proper design of HVAC systems.
After all it’s not just about getting the thing to work but also to work efficiently.

Well then you have not put enough efforts into understanding heating systems.
Just one major point:
If you program stuff yourself, noone but yourself can change, troubleshoot, repair and maintain that.
Including most of the electrical and mechanical parts !
Well, at least noone is willing to so you’ll have a hard time finding some HVAC technician to do it for you as it would be mandatory in many situations:
if you design/operate the heating for someone other than just yourself (like the OP)
if you sell the house
if you don’t have the formal right to mess with electrics or hydrodynamic systems
if you want an insurance to accept your setup

I don’t know. But everybody has the possibility to combine classic systems with OH control like I explained in my previous post.

What a nonsense. But yes, any system can fail, no matter if HW or SW.
And the more complex the more likely it is to fail.

I have to admit, I admire how often you tend to tell me, what I dont understand. You´d rather surprise if you knew better.

Who would care? If I can manage to setup a openhab system to deal with our underfloor heating, then I suspect I can do the same with any other system. It´s not that openhab makes all other options impossible… openhab is just an alternative heating system.
I dont have openhab running our underfloor waterbased heating system. But If I had, and I for some reason wouldn´t be here to troubble shoot or whatever. The family/next owner of the house can always rip off the Rpi and relays, and hire someone to install a “typical” heating controller. If it´s because I have to sell my house… I couldn´t care less about what the new owners think… Why should I? They can change it if they dont like it, or maybe keep it. It´s their decision.

But lets take this heating “thing” to the real life. And then I´ll tell you what I DO know and understand about heating systems.

A water based underfloor heating system is very far from rocket sience. Infact it´s as simple as it gets:
Actuators/motors open when something (typical temperature sensor/thermostat) calls for heating. Thats it…Period!
All other than that is optimizing, which can be based of many things, (time, weather or whatever). And thats what used for optimizing only. Any heating system will run fine without this kind of optimizing.

Our 13 rooms water based underfloor heating system was controlled by a very simple heating system (controller) with analoge thermostats. I changed that, so it is now controlled by our IHC controller.

IHC in short:
Imaging an Rpi wired up to 128 inputs and 128 outputs with logic like NodeRed, (timers, on/off, momentary, push etc. Different kinds of IHC modules can be connected, like dimmers, 24volt output, inputs, converters temperature, lux, humidity sensores etc… Modules are wired up like a bus system.
The controller itself is kinda like a PLC running somekind of Linux which handles all the logic between in and outputs. The IHC controller has a highly powerfull logic to handle a heating system build-in its logic as a finished function blok, (a function blok is a finished template for a special kind of logic).

It will require deeper knowledge in IHC programming to do any changes wether it´s regarding ligthing, hvac, or whatever…
Should I care to having two systems running for heating, ligthning, hvac whatever, because no one else (except electricians with IHC knowledge) can handle the IHC programming? Never! It simply makes no sense… .
I could have setup a 13 room Wavin 9000 controller in parallel with the IHC controller and having doubble temperature sensores in each room as well. Fortunatly, all the temperatures sensores are wired, and ends just beside our boiler and our 13 actuators. So it´s pretty easy to rip off the IHC modules, and install something else. Which is why it simply makes no sense.

Whats important is to let all possibilities be possible… Meaning, whoever comes after me, should always have a posibility to change it in an easy way (as easy as it gets).
I believe its the same, wether it´s a traditionel heating system, IHC, Rpi+openhab or whatever other system a user choose. As long as you make the possibility to change easy, dont ever care about what other thinks or their knowledgde, specially not regarding a heating system, which is a piece of cake dealing with!

Btw… Our IHC system have battery backup, in case of power lost. Most vitale systems will keep on running for hours, including our sercurity system, which is based on IHC as well.
Should I setup a traditionel security system in parallel, in case the IHC controller fails? Naah!

Well, that really depends…
Nothing prevent you to setup an Rpi with openhab for each system you have… But ofocuse, if you use only one openhab to run many systems, then you risc the chance that everything fails, it the Rpi fails.
Thats life - Though as hell, sometimes!

Those kind of systems are “radiant systems” so you don’t have to keep to turn them on and off… it’s not like you turn it off in the morning and then 30 min. before arriving home you can turn it on.

In my opinion you just need to put smart thermostats in order to have the current room temperature and to do little “adjustments” and to have an idea of which zones are active at the moment.

Assuming you want zones of different heating intervals/temperatures that wouldn’t work. A thermostat by definition is a combo of thermometer and valve. That’s acceptable on radiators but in underfloor heating the valve location is in some tech room while the lead temperature needs to be taken off the room the loop is heating.

Not really, a thermostat is a combination of a thermometer and a switch. The switch then normally call for heat (In a small domestic environment). You could have several of these is each room and each turns on a valve which for a zone which will then trigger a call for heat on the boiler.

Interesting, there obviously are different meanings to it. Someone else said it’s a thermometer plus an input handle (or similar) to define the temperature when to switch. Ok, I shouldn’t have written “by definition”.
In radiator heating they’re (usually) combined entities which is a necessity if they work mechanically.
For electr(on)ic ones, you can also have a decomposed system.
In underfloor heating we’re always talking of a decomposed system to have one thermometer per zone, eventually an input element to set target temperature, and one or more loops with a valve each for that zone.
The switch (to call for heat) can be co-located in the thermometer unit, in the central unit (if using a classic controller) or even virtual (in OH).

Whatever. Now all I was trying to say is that you cannot use a unit to combine thermometer and valve in underflooring, you need to have them decomposed.

Many thermostats today (still named thermostats) are simply just temperature sensores, which reports its temperature to some main controller. The main controller controls what will happen from here.
Some thermostats do have buttons and switches, (like a PIR sensor). When temperature reach a specific level, the switch trigger - again to send the message to the main controller, OR perhaps directly to the valve/actuator. Buttons used to set the offset temperature.
And then you have thermostats with build-in logic, switches etc. Logic used to specific time settings like night-time, day-time etc, perhaps even humidity and lux sensor as well.

Point is - The principle is the exact same. It all depends on, where the switches, logic etc. are located, and specially which kind of heating system you have. When you have a heating controller like Wavin 9000 or something simular, you actually only need a simple temperature sensor in the zone the actuator is covering (often a room). The main controller covers all the logic and control the actuators. Wavin´s temperature sensor (wireless) do have some logic for day/night settings. But this logic could as well have been in the main controller.

In my underfloor heating system, (controlled by the IHC controller). All the logic is inside the IHC controller… including day/night, summer/winther etc. Each room just got a simple (wired) temperature sensors. Thats all. It means, that there is no way to change the offset temperature settings from a room in our house. All is controlled by screens/tablets/smartphone connected to the IHC controller (or through openhab, since the IHC controller is connected to my openhab as well). This is a small issue in my house, because it´s underfloor water based heating. It takes some hours from someone changes temperature, until the actualy temperatur is the same in the room. If I had “light” floor heating system, every change will have an effect after a few minutes, which could be a reason to install a thermostat sensor in every room.