Support for Flexit Nordic S4 (IP/Modbus)


Flexit currently have Flexit Nordic S4 model with built in Ethernet, this one support local or cloud connection. Any possibility to have this support Flexit GO support?

On top of this, Flexit Nordic S4 also have MODBUS module:

It wold be nice to have this support. Any help from my site. I can provide tunnel to device.


Hi @Bl00d-B0b,

I created a pull request for that feature: Flexit BACnet - new integration by piotrbulinski · Pull Request #79652 · home-assistant/core · GitHub

Please give it a go and let me know it works for you.


Hi @piotrbulinski,

I’m so glad you have created this integration, I have been now waiting two months for it to be included into the official HA release but now I just can’t wait anymore. Could you help me by sharing instructions how to install this integration from GitHub?


Hi Olli,

I’m planning on finding a way to run it myself from the source code directly. Unfortunately I don’t know of an easy way to run it with stock HAss (which is my current setup using RPi image). I might have some time next weekend to investigate that and I can let you know what I come up with.

Ventilation is the last item to have integrated in my home and it’s unfortunate that HASS core team is overloaded with work and cannot review/merge this integration.



I saw that your pull request on HA-core was closed. Any chance of trying again? Could this be integrated with HACS as a stop-gap?

I am also very interested in getting support for Flexit in Home Assistant. Why was the PR closed? Can I help in any way?

With the amount of work HA core team has, review of this PR wasn’t a priority. I’m not proficient in HA development enough to take several weeks break between iterations to get this done (I need to relearn the HA development process pretty much from scratch every time I look at it). I wish HA would have a native way of adding custom integrations without having to go through their rigorous review process and AFAIK hacks is not so easy to use by non-dev users (please correct me if I misunderstood it).

With all of that in mind, I’m evaluating other platforms where I can get my home automation done (incl. flexit integration) and that’s where my focus is ATM.

After discussing with @lellky a bit, we will attempt again to get the integration merged. Before that happens we need time to fix some stuff and I’ll reopen the pull request.


as a Flexit Nordic owner since a few weeks I say It would really be awsome if you managed to get it through :slight_smile:

It took a while, but I finally found some time to get it to work with the new version of flexit_bacnet library (using async): Flexit bacnet by piotrbulinski · Pull Request #90006 · home-assistant/core · GitHub

Please help with testing and pushing this PR through.


This is great @piotrbulinski :clap: I’m looking forward to using your integration.

I’m currently using this HACS integration GitHub - sindrebroch/ha-flexit. It’s working well, but it’s cloud based and with limiting API restrictions.


I also can help you with testing, as sindrebroch/ha-flexit is limited with functionality, and also use cloud. I prefer to not use a cloud.


How to install this for testing?

Probably @lellky could chime in with suggestions on how to run it locally for testing.
I’m personally following this documentation: Set up Development Environment | Home Assistant Developer Docs

and using this branch: GitHub - piotrbulinski/core at flexit_bacnet

So that’s what works for me:

git clone -b flexit_bacnet [email protected]:piotrbulinski/core.git
cd core
source venv/bin/activate
hass -c config

and after a short while it should become available at http://localhost:8123
Then go to Settings → Devices & Service → + Add Integration → (search for) Flexit

Seems to be right!


Sorry for simple question. I run HA in VM. when I use SSH plug-in it’s not allow me to install. permission deny. maybe you can refer me, how I can get full access?


I’m afraid it’s too daunting for me to install the integration straight from Github to my working setup. So I probably have to wait until it’s officially released. One question though: does the integration support changing the fan speeds? I need this for fine tuning them as the filters get clogged and the pressure difference between inside and outside the house starts decreasing causing all kinds of problems. It would be great to adjust the fans based on the pressure difference (measured with separate sensor).

It won’t allow fan speed adjustment.

Did you try “sudo”? Perhaps there is some HA power user here who could assist - I’m running a stock HA on raspberry Pi and didn’t even try to run this integration there. I tested it only on my PC.

It would be great if speed adjustment would be possible in a future update :heart: