Gas boiler control

Yeah you are eight I should understand my project first. But the thing is I don’t even know where to start so that’s why I’m here.
My boiler has thermostat inputs but it’s not installed. I just bought this house and they didn’t care to install a controlled.
As for the complexity… I find this automation way more useful than trying to control Light switches in my house. I wouldn’t go through all this just to control a light switch.

El El vie, 9 sept 2022 a las 9:31, Markus Storm via openHAB Community <> escribió:

Helklo Vic,
I started with OH mainly because controlling of heating.
I have a very old Vailant gas heater but it regulates heating already by outside temp and is I guess one of the first calorific value heaters.

I let the heater do what it wants as it does a good job in general.
I have installed z-wave thermostats on the radiators in most of the rooms, so I am able to have heating plans for every single room depending on presence.

In my opinion this is a much easier solution as to regulate the heater directly.
As Markus stated, that would be a much more complex approach.

Excuse me but what is the point of turning radiators on and off in each room exclusively? The most sustainable way of saving on gas is regulating the gas heater itself, isn’t it? That’s what most thermostats do: they control the main source directly. Radiators are secondary.

El El vie, 9 sept 2022 a las 11:11, Christian via openHAB Community <> escribió:

No, gas heaters are heating the water until it reaches a max. temp where the heater shuts off automatically.
As more the valves on the radiators are closed as more hot water will return to the heater which causes the heater to shut off.

Regulating the heater itself would mean that some rooms will not get warm enough and some will be overheated.

The placed where I used to live last year was a newly built building and if I wanted the heating to be working, I had to turn on the heater… If I keep the heater on 24/7 during the winter and there’s no temperature control in any room (no thermostat), the heater will keep the water at say, 70 degrees… but it will do that constantly… that’s a waste of money.
Thermostats turn heaters on and off, not radiators. I really don’t get your point.
This wasn’t the point of this thread anyway… so far I haven’t got much help really

El El vie, 9 sept 2022 a las 12:23, Christian via openHAB Community <> escribió:

Okay, so you are looking just for a solution to control your heater where I cannot help you.

Just for completeness:
Modern heaters regulating heat depending on outside temp.
If it is not so cold the water has e.g. 35°C, if it is colder up to about 60°C are possible.
The valves on the radiators take care to have the wished temp in each room.

Why can’t a thermostat control a radiator?

If you just want your heater on at certain time then use a time clock.

You have technology and specified technology and are lost.

What do you want to do?

Maybe your question should be

I have a boiler 27525hjknfns link with EBUS protocol and want to control it using openHAB where should I start.

I want it so when I am not home and it is cold outside or predicted to be cold it will turn on automatically to RR deg because I have pets I don’t want to freeze. When I am home I want it set to TT deg in the day and EE deg at night because I like it like that. I also want a holiday mode so when there are no animals in the dwelling it will heat only to EE deg so the pipes don’t freeze. I would like to be able to override the settings with my voice when I want to.

Yeah it can all be done using openHAB


Yeah exactly, I probably started off on the wrong foot.

Basically what I have is a Hermann Micraplus 25 with EBUS protocol and I would like some help on how to control it with OpenHAN and a raspberry Pi, and I don’t know where to start or what componentes I need.
I have been checking dry relays but I don’t know what kind of relay I need, if it need to be a sonoff wifi relay, etc.
I just don’t know where to start!


El El vie, 9 sept 2022 a las 13:49, James Bowler via openHAB Community <> escribió:

Sure we can help

It depends on what control you want. If you just want to control when it is running you may be able to use the dry contacts. It will act like an electronic switch that you can control instead of the mechanical one.

I would use the EBUS as you can then control everything.

Okay so if I want to use the EBUS what kind of dry contact do you think I need? Also, those dry contacts require some power? Do I need extra wires for that?

El El vie, 9 sept 2022 a las 14:07, James Bowler via openHAB Community <> escribió:

You will need something to connect to EBUS like

Or build your own.

Ok this is pointless. You are showing me an adapter for my Raspberry that’s not even available to buy. Also, I don’t know what kind of relay I need to connect to my heater…
On the page you provided it says the heater needs to connect to the EBUS adapter that I have to buy an attach to my raspberry… I just don’t want to place the raspberry in the room where the heater is. It is somewhere else
This is exhausting. Thanks anyway.

Read the EBUS binding info. It gives a lot of information.

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.

By a lot of information you mean “the corresponding hardware is required”?

El El vie, 9 sept 2022 a las 16:51, olaf via openHAB Community <> escribió:

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 <> 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
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.

There are plenty of manufacturers selling wireless OpenTherm thermostats

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.