Max! Thermostat & TRV linking

I’m new to Homegear but I have set it up on Openhabian using a CC1101 to replace my very unreliable Max! Cube. To start off I paired one thermostat and TRV successfully and they are appearing in Openhab dashboard. However, changing the set temperature on the thermostat does not update the TRV - how do I link the two devices so that they work as a room?
Also, is there any method of changing the schedules for each room?

Hey @sota,

dou you mean the wall thermostat (TRV)?

As far as I know, you can’t send SET_TEMPERATURE to one device so that the linked devices get updatet. You have to send the desired temperature to every device in a group.

Only if you change the temeperature at the device, it will get send to all linked devices.


Using the Max! Cube, I could increase the temperature on the wall thermostat (or in the app) and have all radiator valves (TRVs) in the same room copy this setting.
I’m trying to get this to work in OpenHAB or in Homegear but the thermostat and TRV devices act independently.

You can link them with (e.g.) the Homematik-Konfigurator. But this will not send SET_TEMPERATURE to the linked devices.

OK, that is a pity. I will have to go back to using the Max! Cube as this is no use if I cannot use the wall thermostat to set the valves.
Thanks for your help!

Sure you can. Either link them directly and use the communication between the devices or write a rule in openhab which uses the temperature given by the wall thermosatat to set the temperature of the valve’s.

You can also use homegears’s node-blue for this.

Thanks @pmayer, I have only been using homegear for a few days so I am still learning! I have tried to link the two devices directly, but this does not work - perhaps because they are already linked to homegear?
Creating a link in OpenHAB Paper UI is a bit better but still the wall thermostat does not update the TRV. I have looked at node-blue, but I cannot find any documentation for it and there does not seem to be any nodes available. It looks a lot like node-red which I am familiar with.

It is the editor taken from node-red with a homegear backend.

To link the devices directly you can use the Homematik-Konfigurator. They can be linked together and to homegear at the same time.

You can build the logic in OpenHab, but I think you must write rules for that.
For node-blue make sure, you’ve installed homegear-nodes-core.

Thank you for all your advice, I have tried Homematik-Konfigurator and I could not get it to work. The other options seem too complicated to make work reliably - I need a simple, reliable solution that my family will be happy with. Also, a lot of the documentation & videos are in German which I unfortunately do not speak.

I have been doing a lot of research over the holidays and I would like a little more advice if possible? I have discovered that there is also an option of Homematic and Homematic-IP devices from eq-3, what is the difference?

It looks like it is a more “professional” solution, and it gives me a lot more options, for example to control the boiler and zone pumps in my home. However, the OpenHAB binding does not support the CCU so would Homegear work with this without the linking issues I have had with Max?

Many thanks and Happy New Year!

Sorry sota,

but you are mixing up various things.

If you want a “simple, reliable solution that my family will be happy with”, maybe then tinkering with different systems is not for you. A well built “ready” solution for valve thermostats is (e.g.) Tado: - maybe have a look there.

Homematic IP is a different protocol than Homematic. Refer to the eq-3 site for more info: and
Max! is a third implementation in the 868MHz spectrum from eq3 but not compatible to homematic nor Homematic IP.
Thats where Homegear, as a versatile solution to build the hardware adaption of different protocolls, jumps in - it is a complete open-source replacement for the CCU (currently no Homematic IP).

OpenHab tries to do a similar thing but often relies on the official gateways of the manufacturer. The openhab-homematic-binding works very well, I can not see why you say it does not. It also works completely with homegear including auto-discover and so on.

I understand that the most part of the documentation is in german, but please try google-translate for this. Sorry that I’m not willing to accept that you did “a lot of research”…


Thank you, I had misread the readme for the binding - it says “The Homematic IP Access Point does not support this API and can’t be used with this binding.” and I was unaware of the difference between Homematic & Homematic IP. I think I will return the Max! items I have and exchange them for Homematic.

I already have a very stable OpenHAB system that “just works” - apart from heating control - so I want something that will fit well with this.

If you doubt the amount of time I have spent on this - then ask my wife!!

Lol - hope she’s not mad :wink:

The Max!-devices will be shown to openHab like Homematic-valves once paired to homegear. All in all this is not a complex setup, so give it a try.


When we came home on Christmas eve and the house was freezing, she wasn’t mad, just crazy!:angry:

My 30 day return for Conrad expires tomorrow, so I will return the Max system and read some more and then decide.

I will let you know. I forgot to say that CC1101 SPI adapter worked very well on the Pi, I wish the rest of the project went as well.

Don’t make it hard for yourself. I think you are halfway through… I for myself use Max! over homegear. Though that I’m now using node-red, I’ve startet with openhab. So this will work without a problem. They are not the best valves, but the eleven in my apartment are working for over 1,5 years now without any failure.

If you wan’t to go the homegear way I suggest buying the “normal” homematic valves, as they are better in quality over the Max. If you’re on a budget stay with the Max!, they will do.

I am using Node-Red to run my rules and scripts for OpenHAB. It’s much easier and more flexible that way.

The deciding factor on Max! for me was that I have 3 heating zones plus hot water, and there is no easy way to start the zone pump when a valve is calling for heat. It looks like Homematic can do that and I can mount some of it in a DIN rail box.

Once I get it working, I will look again at homegear.

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If you want to go Homematic, i suggest the ELV-Shop and have a look at the ARR-Kits. You get the radiator thermostat for 30 €, the wall thermostat for 35 €. The ARR-kits are easy to build, about 10 minutes, no soldering. (This is only valid for ARR kits, others differ!)

ELV is the parent company of eq-3, or at least both company are bound together quite tight.

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Thank you @job, those prices are very good, I will order from them.

Before I place the order, you say the ARR kits are easy to assemble, what does this mean for this:

ELV Homematic ARR kit Central CCU2 for Smart Home / Home automation incl. 12 months CloudMatic connect

Is it a set of parts, or is there a bundle with CCU2 and valves that I do not see?

I don’t know about the ccu2, other than it is not needed. Use homegear as a substitute. My ccu2 is offline since switching to homegear.

I built the wall thermostat, radiator thermostat, keything, wall plug and maybe some more. all of those were just clicking a few parts together.

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Please be aware, that Homematic IP is not supported by Homegear. If you want to run Homematic IP with openHAB, you need a ccu2 or Raspberrymatic. If you want to run openHAB, Homematic is the better choice.