ebus support for boiler

[ChrisP]

Hi,

I'm pretty new here and hope I'm posting this in the right area. I'm starting to implement home automation by curiosity and try to have a step by step approach, being pragmatic and adding real use case to my system. I'm playing with various automation distribution, and for now the one I'm the most confortable with is Domoticz. I tried it on a BananaPi, and moved it to the Synology. I really like it !

What I miss the most now is the lack of interaction with my boiler to be able to manage it remotely, so that I can change the temperature just before coming back from holidays for example.

So what I would love to see is ebus integration in domoticz.

What is ebus ? ebus is a communication protocol used to manage several boilers brand, like Vaillant and Saunier-Duval for several years now. ebus is interesting because it's the native language for this boiler, so that you can get a lot of information directly, like inbound/oubound water temperature, activity of the boiler, temperature target of the thermostat ...
It can also be used to change the target ambiant temperature, switch it off ...
Some information regarding ebus can be found on this wiki: https://en.wikipedia.org/wiki/EBUS_%28serial_buses%29

There are several ways to physically interface with ebus, using builtin like these one: http://www.eservice-online.de/shop/en/p ... oppler-usb or building dyi interface like the one descrided here: http://ebus-wiki.org/doku.php/ebus/ebuskonverter

Regarding protocol itself, a daemon already exists here: https://github.com/john30/ebusd. There are also good works done on openhab distribution. Maybe a common work with them can be possible ?

So maybe a clever way to integrate ebus in Domoticz could be to interface ebusd so that only the logical Domoticz should be worked on ?

Is Something like this in the focus of Domoticz ? Would other users like to see such a feature ?

How can I help ? I'm not really a programmer, especially in C++, but I can help to try beta versions on my boiler if needed, dedicating my BananaPi for testing it (starting with read-only activities to minimize risks ^^).

Thanks for your feedbacks on this proposal.

[gizmocuz]

c++ would help to get this implemented

have you considered buying an opentherm gateway ?

[ChrisP]

Hi Gizmocuz,

Yes I had a quick view on Opentherm Gateway, but my understanding is a bit redondant and different of what is allredy implemented through ebus.

My Boiler is connected to an intelligent thermostat (VRC470) using ebus interface. This thermostat use an external probe to determine the external temperature and humidity then calculate what is the optimum outbound water temperature, while the target ambiant temperature determine when the circulation pump should be activated. Of course there are programs to change the target ambiant temperature depending of the hour and the day of the week.

But in addition, it support some sanity check if the boiler is working in unsafe manner to shut it down in case of emergency.

(To have an overview, the user manual detail everything here: http://www.vaillant.co.uk/downloads/vrc ... 261429.pdf )

There are some value I would like to monitor, especially Water pressure, System Status, Air quality sensor in ventilation in order to trigger notification in case of out of spec values. All these information are allready gathered by the boiler and transmitted through ebus interface. I do not know how to get these using OTGW.
And as I said, I would like to modify active program or change ambiant temperature target in order to lower gas cossomption while travelling and setting it back just before coming back.

So In my opinion, OpenTherm Gateway is not the adequate tool for that. Am I mistaken ?

[ChrisP]

In addition I had a look at the ebusd sources on github, it looks like c++

[gizmocuz]

It seems the deamon will create a tcp server where you can connect to
did you try the deamon and checked the output ?

I did not see anything related to temperature, humidity, pressure etc...

[ChrisP]

No, I didn't try it since I do not have devices to connect to ebus and wanted to have some feedback about domoticz potential support before purchasing anything.

How ever it looks like I need first to make a diy one first to do some experimentation.

I'll go this way and will come back once I'll be there.

Thansk for your consideration.

[Barberousse]

Hello,

Just to let you know that I'm writing a python plugin to connect my Vaillant ebus boiler to Domoticz. It communicates with ebusd (https://github.com/john30/ebusd) and should work with most ebus boilers. Right now, I'm able to read most register and write some. I think I will publish the plugin on github during December or January.

[Barberousse]

The ebusd plugin is here: viewtopic.php?f=65&t=20625