Modbus integration for ISG-webinterface - STiebel Eltron heatpump

Developers
1

Hello,
a few month’s ago i have created my own app to connect our heatpump to homey. Since then i have been active using it. All seems to work great.
I’am using it to adjust mode, heating temp but also to adjust heatwater temperature to use as much sunpower for heating it instead of buying current.

I really want to share but have to less knowledge about releasing it and more important offering support. Is anybody willing to take over this app? So more users can interface their heatpump?

2

It’s not mandatory to offer support.
If you consider to publish the app,
here’s a how to:
https://apps.developer.homey.app/app-store/publishing

3

That is great, @H_van_Barneveld !
If you can publish it, it would be great I am looking for such an app.
And I am willing to support. I did some programming in C and VisualBasic. Unfortuntely I am totally not familar to JavaScript or HomeyScript and how to create or maintain apps for Homey. But at least I could offer some help by translating into German (French and Italian would be awful, but probably better than nothing and and a motivation for others to step in :wink:)
Regards Dirk

1 Like
4

I tried to publish. as soon it’s reviewed it will be published officially. For now it’s available as test

5

Done

6

Thanks I already installed it. And it works instantaneously :rofl:
My understanding for creating your heatpump device. Anybody should feel free to correct me:

  • find the ip adress of your ISG. I found it under servicewelt on my router. It is very important that you configure it as a fixed ip on your router. Otherwise you may lose it frequently.
  • The port seems to be always 502 according to the manual.
    This number I also find under diagnosis->system: FES / SOFTWARE in the web-interface. Could be a co-incidence. Otherwise if 502 does not work, it might be a hint where to look for alternative entries.
  • the modbus ID seems simply to be the number of your installed device. As I only have one heatpump, I tried 1 and it worked.

So now I can set the heating temperature and the operating mode. But as the stem is totally in summer mode due to external temperatures I cannot check any effects.
So probably I can check in autumn.

7

In summer i manage max water temp according our PV powerinput. so normally it’s set to 50. as soon PV start loading to grid i reset this to max.
I add your input to readme information.

1 Like