Compatibility Fritz! Radiator and e.g. Z-Wave / WiFi Components


I’m new here, and hope that the following post is correct under configurations.

I have already for a while various Fritz! Radiator thermostats in use on my Fritzbox 7490 (Comet DECT & Fritz 301). For info, I also have several Fritz! Sockets and a simple switch.

Now I would like to attach window sensors so that when the window is opened, the thermostats turn off. I am aware that there is a time delay due to the polling interval of 15 mins. (in the worst case). In total I would need 5 window sensors. Currently I live in a smaller apartment, but it should be usable for a house later if necessary. As host for HA, I had imagined a Raspi3B.

Now to the actual question:
The Fritz! Thermostats are set so far.
What options do I have for the window sensors?
Which technology can be combined with this? Z-Wave (Aeotec?), WiFi? DECT (telecom sensor)?
It would also be ideal if I could then expand the system with other sensors such as humidity or temperature.

Primarily I’m looking for info on what really works with each other and if anyone has already tested this successfully. I just want to avoid buying anything that then does not work.

Thanks for constructive help. I have been looking for some time for helpful information and something that can be implemented “relatively” easy.


For those kind of sensors, I’d suggest the zigbee protocol with xiaomi sensors.

Zigbee is very well supported in HA. You only need a dongle like this one: SMaBiT: Computers & Accessories hooked into a RPI, with the zigbee integration ( Zigbee Home Automation - Home Assistant (

Xiaomi produces good and cheap zigbee sensors, including doors and window ones, e.g. Xiaomi Mi smart plug remote control socket: Camera & Photo

You DON’T need to use any hubs if you use the kind of dongle mentioned above!

You can also use wifi or bluetooth sensors, but those tend to be less reliable, consume more, and have less range.