I recently ordered one of the DECT radiator thermostats for the FritzBox out of curiosity.
As usual with Fritz products, installation and commissioning was super easy. It takes less than ten minutes to install and set up.
All kinds of options can then be set in the app and the FritzBox interface. These include fixed times at which the radiator should be switched on. Unfortunately, this option is not so practical for me. What I have always done very well in the past, however, is to switch on the heating when it is cold outside (for example, cooler than 15°C) and the TV in the living room is switched on (as a kind of presence detection).
I wanted to have this "dynamic" switching behavior again. In the past, I did this with a few nodes in NodeRed. Thank goodness there is also a suitable node for controlling the Fritz heating thermostats. You just have to configure it accordingly.
You can find an example flow for controlling a Fritz DECT radiator thermostat in this article.
I know the following notes are always kind of annoying and seem unnecessary. Unfortunately, many people who knew "better" have lost eyes, fingers or other things due to carelessness or injured themselves. Data loss is almost negligible in comparison, but even these can be really annoying. Therefore, please take five minutes to read the safety instructions. Because even the coolest project is not worth injury or other trouble.
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So that you can install new nodes, NodeRed should of course already be installed.
How to prepare a RaspberryPi and then install NodeRed on it is described in the following articles.
The following three articles describe what needs to be done to prepare the RaspberryPi:
RaspberryPi – setup for nerdiys!
RaspberryPi – The first configuration!
RaspberryPi – Control the RaspberryPi via SSH
NodeRed – Installing NodeRed on the RaspberryPi
NodeRed - import and export node code
In the following list you will find all the parts you need to implement this article.
Log into the NodeRed configuration interface
Before you can edit your NodeRed configuration, you must - if activated - first log into the NodeRed configuration interface.
Install the appropriate FritzBox node
In order for NodeRed to communicate with the connected radiator thermostats, you must install the node "node-red-contrib-fritzapi". How to install nodes is described in the article NodeRed – Install new nodes described.
NodeCode for controlling a Fritz DECT radiator thermostat
The current status of the NodeCode is my first draft of a control system. I will certainly continue to work on it. So please ask for updates if this post has not been updated for a long time.
In the current version, you can display the temperature measured at the radiator and the setpoint or target temperature. Of course, you can also set the desired temperature.
Last but not least, the charge status of the batteries is also displayed in the radiator thermostat. I assume that this is displayed as a percentage. However, as the charge level is currently at 100 and is falling very slowly, I still need to observe how this value develops as it falls.
What I have already installed but have not yet been able to trigger is the boost function. This function can be triggered on the thermostat itself by pressing the menu button for two seconds. This heats up the radiator fully for a short period of time. Of course, it would be practical if this could also be triggered from NodeRed to heat up a room quickly and automatically.
Below are a few views of the configuration and the actual NodeCode.
How you can import the NodeCode below is described in the article NodeRed - import and export node code described.
As always, you can find the NodeCode in the Nerdiy Git repository under the following link:
Have fun with the project
I hope everything worked as described for you. If not or you have questions or suggestions please let me know in the comments. I will then add this to the article if necessary.
Ideas for new projects are always welcome. 🙂
PS Many of these projects - especially the hardware projects - cost a lot of time and money. Of course I do this because I enjoy it, but if you think it's cool that I share the information with you, I would be happy about a small donation to the coffee fund. 🙂