Offline control for Viessmann Vitocal 200-S

I am currently in the process of selecting a new heating pump for my house.
I was offered a Viessmann Vitocal 200-S. Now I’m trying to find out if it would be compatible with OH3. They offered a “Vitoconnect OPTO2” module that connects it to the local wifi. The normal use case would be to use their ViCare-App and have the heating system always connected to the internet. I found openHAB bindings that communicate with their cloud server and many topics about that.

However, I don’t want to have the heating system always online - for security, reliability and dependency reasons.

My findings regarding this topic are rather confusing, so please excuse me seeking help in this topic with such basic questions, but I really hope that someone is already in this position and can shed some light on this topic.

  1. The “offline” binding for Viessmann heating systems is apparently this:
    Vitotronic - Bindings | openHAB
    Is that correct?
  2. The second component seems to be “optolink”, but it hasn’t been updated for 5 years now. Is this still a fully functional solution?
    GitHub - steand/optolink: optolink adapter to vitotronic for openhab2
  3. Am I correct in assuming that I still need the “Vitoconnect OPTO2” component, that I connect to the heating system via their V-cable and to the local network via wifi? I would then cut its internet connection through my router. Will it still work and communicate offline with the software components from 1. and 2.?
  4. Are there any limitations or problems with this approach? I’m confused, because this seems to be the only logical use case as most openHAB users assumingly prefer solutions without cloud-dependencies. But in this case, I found more about the cloud-based binding rather then this offline binding.

It is really important to me to clarify all this, because I don’t want to buy something so expensive just to find out that I cannot use it without limitations or at all in OH3.

Thank you very much!


1 yes
3 yes
4 some tinkering around around building optolink by yourself

I own Viessman Vitodens 200W with optolink. I have scratched the optolink interface from some spare parts and ESP8266 based on some instructions from openv wiki from github. For now it connects successfuly to my vitodens, pull the data and pushes it to mqtt. It costs me in parts about 15$/10eu.

Original optolink was too expensive for me.

I’m a user of the Online version (using VitoConnect 100).
Viessmann did publish an official API this year which enables to get some information/ set some functions which are available via the ViCare App, BUT not all. The selection even depends on the specific heating device. As published more function will be enabled on “request with detailed reasons’”. Such happened after the API start, will it continue to happen??
Additionally Viessman does NOT assure that this “service” will remain without a price-label or at all.

I will keep the Online version for the first five years ( prolonged waranty for using ViCare).
After that I am considering the Offline version!

A binding for the Online version is being build ATM (alpha version).

  1. Yes
  2. I don’t know.
  3. I would say no. You only need a optical probe.
  4. At the moment I am also using the Online version with Vitoconnect. Because vissmann gives you an extended warranty when you use it.

Over all I have to say I am not super happy with the heatpump. Two reasons:
#1 energy consumption: The heatpump has an energy consumption of about 70 W in standby. Many owners are complaning about that. There is no real soution. See here in the german forum:

or here:

#2 no “real” local API.