Hi, I have also spent alot time thinking about how to control my Junkers Heating a bit more smart. I also planed to build an Arduino based controller on my own to completely replace the existing room controller (TR100 in my case). But last year I found the Tado Smart Thermostat as replacement for the TR100 which covers all my needs out of the box.
- Perfectly compatible to almost all Junkers Heating especially the ones which can be controlled by a TRQ21 or TR100
- Individual Heating Plan for every day
- Automatically Switch to Away mode by GPS Location of the Smartphone
- Manual control
- Early Start (start heating when I come clother to my home)
- Perfectly integrates with Homekit, Alexa, IFTT and openHAB
- a nice smartphone APP to configure everthing and see stistics
- Not too expensive
- Works out of the box without the trail and error a self build themostate would bring until it works as expected.
Especially because of the presencedetection in combination with the Smartphone app I use a very simple heating timpleplan. Only day and night, all other things like work, holidays etc works automatically.
There are also Tado Radiator Thermostats but for this I use the much cheaper MAX ones controlled by homegear. OpenHAB Switches the MAX thermostates to ECO mode if the Tado Thermostat is in Away Mode.