I think you are missing the point as you are too fixed on the dry contact aspect. If you are using the ebus approach (which gives you much more control of your equipment) you do not need any contact as it would be doing the work. The option suggested is just an option, you can search for a brand specific ebus adapter and see what those options are.
If instead you decide to skip the ebus method and use something like a dry contact, how are you planning to control it? Timer, sometime of sensor, thermostat, or just presence based (with heating I would probably not go with this method as it will be much more work to reheat it).
Honestly, it sounds like you need to do more research on your project and be more open to the suggestions given. If all you are wanting to do is have it turn on and off at set times and do no other automation, then openHAB might be overkill for your needs and something like a timer might be a better option. If you plan to do more automation and are potentially interested in controlling both the boiler and the radiators then stick to openHAB.
I was thinking of a dry contact because my idea is to have a zigbee thermometer in each room and depending on the average temperature of all of them, heating will turn on and off. A timer is therefore out of the question.
Also, I don’t want to buy into an Amazon Thermostat because those usually offer little to no customisation.
El El vie, 9 sept 2022 a las 17:02, Josh via openHAB Community <bot@community.openhab.org> escribió:
For your use case I would do a mixture of both controlling the radiators for each room and use the ebus to control your boiler. You might actually be wanting to lower the heat versus turning it off completely. If you let it get too cold it will actually take more energy to get it back to temperature verses just lowering the temperature so it is not over heating.
If you can get access to a second pi (ideally around msrp so not over spending) you can set that up by the boiler and have your main pi located somewhere else in the home. This might be the best of both worlds.
If you are set on a dry contact type application the FortrezZ MIMO’s work pretty good but are Z-Wave instead of Zigbee…
The link about the E-Bus binding gives information how to use the binding and setup communication. Also is shows Binding compatible E-Bus interfaces. Basically all information is provided to achieve what you want as far as I see. I would stick to that to begin with.
But I have to agree with Markus in one of the previous post. If you have no Openhab experience it can be a steep learning curve.
Think good about what you want to achieve, It’s not easy to make a fully functional thermostat within Openhab.
For example I have a programmable Thermostat that is doing what is should do. I can control and set the theromstats program’s and temperature within Openhab to add a extra “If no one present set temperature low “ feature and to control from outside my home
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Depending on your house and personal demands a lot of people have a “smart” thermostat per room. So only the rooms that require to be heated will be on. The Gas Heater will regulate his temperature depending on outside temperature, water flow and returning water temperature. But your Gas heater will need to support this of course.
You could also look at the Tado system which provides individual room temperature control on each radiator, combined with a common (wireless) on/off contact to switch the boiler on when at least one of the room radiators is calling for heat.
EDIT: ps the Tado system is rather cool since it does also have a wireless receiver that can turn on/off you boiler via OpenTherm; which would allow you to also have an OpenTherm gateway to monitor everything.
