WTH UMR Vario - Dutch Floor Heating Topic

Hi community,

Starting thread for the user community of the lovely dutch floorheating controller from WTH: The UMR Vario (v1). I am new to Home Assistant custom integrations, but on a quest to provide home automation for this older product. See the threads on thee WTH UMR2, which already has custom integrations (written by the open source community. This thread is not for the UMR2, but the older (~2010) UMR Vario.

What i have sofar in terms of working towards an integration with Home Assistant:

  • List item USB (mini): The UMR Vario has a mini usb port which, according to manuals, can be used by installer parties to debug, read values and configure the Vario. Based on internet research the software is called VarioControl. I have not been able to verify this, nor find any more information about what the software is able to read or write to the controller. Without installer software its is just a device on a COM1 / Serial Port.

  • List item Bluetooth: Ditto as the above; standard bluetooth client doesnt show much info; it just pairs and waits for the installer software to start doing something.

  • List item C1101 RF: The main living room thermostat communicates over 868mhz. Its an older board (2010), so my theory is that the signal likely does not contain rolling code implementation, so learning and resending the same signal will likely work. This is currently not confirmed

Currently my main use cases is to have access to read information on all thermostats in my house and at a minimum be able to set temperature on the living room thermostat. This could technically be achieve by just sniffing and learning RF signals to the main thermostat (which in turn talks to the Vario’s C1101 RF module). However that would limit functionality to only the living room temp info and the features it contains (on/off, set temp, heating/cooling) and not give read access to other room temperatures.

I am currently still in research phase and want to work out what info is available, who is interested in this integration and if we can get WTH to collaborate. Based on that i will decide whether to reverse engineer the RF signals (and stick with that) or use a Serial Port Analyzer to reverse engineer that and then plug it in a Pi (for example).
The Serial Port option basically follows what this user did in Domitica with a Pi: DomoticaVrijgave - WTH wiki and the Homebridge add-ons here: https://www.npmjs.com/package/homebridge-umr-controller?activeTab=code However, i cant work out how and where his NodeJS server is interpreting the serial messages communicated. Does homebridge take care of this? Maybe someone with more serial SRE knowledge can assist us here.

Any information welcome and also please share if you are interested in this integration.

Happy automating!

My Vario = UMR-T FW-ver (Firmware Version): 02b07, so hardware 02 and firmware v7 - based on this source: DomoticaVrijgave - WTH wiki

UMR Vario V1 super-user / installer code (e.g USB/Bluetooth config or learning new thermostat: 8502.

Full option menu here: D9350_Programtree_monteur.pdf