Integrating Immergas Vitrix Superior 26kW ERP2 with Home Assistant for Metering

I have been involved with HA for a relatively short time. My experience closes in putting up HA as a Docker on Debian and integrating a few basic devices (PV inverter, air fresheners, garden watering system, in order to log the parameters in the InfluxDB database and thesis pushing out the PV installation params to the PV monitor service.

I would like to include the parameters of the condensing furnace, i.e. mainly CH output temp, CH return temp, DHW temp. The furnace is Immergas Vitrix Superior 26kW ERP2 . I was thinking of two possibilities, one of which seems to me to be a total abstraction and rather impossible to jump through without help:

1. the cooker already has some automation, there is a controller connected to it by cable and the controller can do quite a lot, including scheduling DHW and CH separately. It shows the DHW tank temp, supply temp, return temp, you can change a lot of settings with this controller, hence I thought that since the furnace exchanges information with the controller via cable, it could also exchange this information with the HA, but I couldn't find any ready-made Immergas integration among web resources. Hence the idea of programming this from scratch, but I don't even know how to go about it and how, with what, to eavesdrop on this controller protocol to extract the information I need. In addition, you'd need to make some kind of translator that would send the information over the network to the HA and such a thing is probably done on a RaspberryPI or Audriuno (if I'm typing silly things, forgive me).
As well as a connector on the motherboard for the controller, the oven also has some sort of connector for the BUS, but as there is no documentation available on this other than the one diagram below, it's hard to see what this is for.
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2 Well the other plan is to invest in some WiFi gateway , which will allow me to bring out a couple of cheap thermistors that I can attach to the plumbing pipes and thus send measurements to HA over their network. This seems easier to me and, although poorer than full integration with the furnace, is sufficient for me. Do you know of any low-cost solutions for such temp measurements that you could recommend that would not cause a problem to integrate with the HA?

Thanks for your help.

Re.1 I am not aware of anything. Maybe it uses Openthem or its own protocol.
Ad.2 Many possibilities. Any ESSp8266 and sensors e.g. LM35 or DS18b20. Easily done on e.g. Tasmota or ESPHome software.

Thanks, my understanding is that the ESP8266+sensor module is one independently working thermometer communicating over WiFi, as the ESP8266 has one analogue input, and not sure if there are solutions to plug multiple sensors into one WiFi module?
From what I've explored you can add an ADS-1115 expansion module to the standard ESP8266 module increasing the number of analogue inputs to 4 pcs.

ESPHome is an add-on to HA and you add the device there. Do I understand correctly that I then configure the device remotely from the ESPHome add-on in HA and do not need any other programmers?

Yes. The ESP8266 has one analogue input. To have more you need, for example, an ADS-1115.
On the other hand, DS18B20 are digital sensors and there can be even dozens of them on a single 1wire bus.
EspHome is an add-on in which you build software for esp8266 with the modules you need.
I prefer Tasmota, which you basically upload to the esp8266 and configure later via the web panel.
Tasmota communicates with the HA via MQTT
To program the esp8266 you only need a UART cable or a microusb cable (e.g. for the Wemos D1 mini boards)

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The project has started, tentatively the prototype looks promising, thanks for the tip.
I just have some problem with the router, it kinda keeps disconnecting from the wifi of this module. Once it connects, it's ok, but when it restarts it can get into a pileup and breaks the connection every 10 sec.

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Read the logs from the Tasmota console. There it should write out what the problem is.

Well, from my own. I wrote to immergas Poland. They were able to describe as much to me.

"The boilers of the Superior series communicate with the controller via BUS protocol, 15-24 V supply.

We do not have details of the protocol itself, I assume it differs from dedicated protocols."

Representation for Poland. I don't assume in advance that they don't know, maybe they can't share. Surely such a Tybox controller manufacturer knows the protocol, because they officially support this cooker.