Hello,
to save some money i was thinking to use Zigbee window sensor from other brands, instead of the homematic sensor.
I have RaspberryMatic and Home Assistant running on a RP4 with Docker.
Is this a good idea?
HA can automate and turn of the heating if a window is open right?
Only disadvantages is that RaspberryMatic can’t automate this. Any other disadvantages.
Thank you for your help.
I dont use Homematic or Raspberrymatic - I understand the concept - an addon replacement for your Homematic CCU - so I’m making some general assumptions that it’s how you connect to your thermo and we will also assume it’s working as designed and you have entities in Home Assistant from it that you can automate there.
Not only can it - this is what HA was designed to do - integrate devices from disparate ecosystems into one single control system.
This is the part I dont understand - Raspberrymatic should allow HA to do this?
Also - just a helpful word of advice - pull your email address out of your community profile in that line. It’ll get scraped up for junk mail within a few hours if you don’t
Thank you for the feedback and the hint with the mail address. Don’t know why it was there. 
RaspberryMatic can’t automate this
If i use Homematic window sensors, i can automate turn of heating by window open, direct. I can build a group of thermostats and window sensors and the devices do not need the the central (RaspberryMatic) to do the automation.
The devices talk direct to each other.
This is the only advantage if i use the original Homematic sensors.
I will buy one Zigbee window sensor and will try the automation and how good it works.
If you use the Homematic IP Local Integration you can use a service call to tell HomeMatic that a window is open so it will reduce the temperature in that zone. Have a look at this one https://community.home-assistant.io/t/homematic-ip-local-bind-a-custom-window-sensor-to-thermostat/474028
Ok great.
I already have the HomeMatitic IP Local Integration running.
I am using the window sensors from my alarm system to trigger the HomematicIP heating groups to set the window open state. This then drops the set temperature for that group.
Works flawlessly.
What if you set the temperature to heating, while the window is open?
How to lock the HM Thermostat to „no heating/ low temperature“ while the window is open?
I am thinking to replace the Homematic heating components with only zigbee.
Is it possible to connect (binding) the Zigbee window sensor, radiator thermostat and wall thermostat direct with each other. So they will communicate direct with each other?
Why i want that. Controlling the heating should also work if Home Assistant is down.
Can someone recommend a wall thermostat with Zigbee (preferably with batteries)?