I have a new heater from Buderus. An MX 300 WLAN module is installed for communication. You can control the heating via an app. Is it possible to integrate this system via Nodered?
You might try looking in the Home Assistant community if anyone has integrated the unit. This might give you the information how to control it from nod red.
I do not know the MX300 interface and what its possibilities are, but as Buderus is part of the Bosch concern, your new heater is equipped with the EMS Bus.
I recommend to interface directly with that EMS bus. You need an interface unit.
I own myself an older version, based on a ESP 8266 board, together with a Nefit heater.
But have a look at that hardware: https://bbqkees-electronics.nl/
As @ghayne already said, if you look to the Home Assistant forums you will see that the unit is also used there. The software is developed and maintained by proddy. See: proddy (Proddy) · GitHub
The unit can be powered from the EMS Bus by means of the Service Connector.
You need a wireless signal at the heater spot..
The unit has a web server for configuration and provides MQTT protocol.
In Node RED you can manage that further.
These are important tips. If I get any further I will share my findings.
I would like to briefly tell you about my experiences.
The tip was great and so I found it on eBay. This board is exactly the solution. The part can be connected directly to the heater's EMS bus. The level adjustment for the EMS bus is already in place. A temperature sensor can also be connected directly. Furthermore, additional GPIO can be configured via the interface. For example, I connected 4 x GPIO for window contacts. The board was professionally manufactured. The ESP-32 is already flashed. The data from the EMS BUS can be integrated into Nodered via MQTT. An important feature: The part works bidirectionally, so you can send commands to the heater via Nodered (MQTT). Since the ESP has its own web interface, the heating can also be read or controlled without Nodered. These are my first experiences.ebay