I should not have looked at this… now everything else seems inadequate…
(of course this would be not only for the heating system, but for the house.)
Unfortunately this is too expensive for me at the moment. But since there seems to be the possibilty of a future version of iotawatt with ESP32 and with even better ADCs, I would want to wait for this anyways.
So for now, I will probably go for some solution with the PZEM-004t modules or with one or several Shelly devices.
Just for background information:
The main reason I wanted to monitor different parts of the heating system is, that there are problems with it. It belongs to my fathers house, and it sometimes stops with an error message. He already had to pay several thousand Euro to the professional serviceman, who also mainly seems to change part after part.
And there are problems not only with this system, but with another one, too. The heating of the nearby church community center had even worse problems, until now there have been four different companies working on repairing it.
It was the reason I started with Home Assistant: First I installed several temperature sensors, so I could see it from my home, if the heating failed in the community center. Then I build and installed an automatic physical button-presser to restart the heating system. (heating stopped with error-code, if you pressed a specific button on the device in the basement, it restarted).
If the temperature sensor was below a certain value for some time, a home assistant automation activated my physical button-presser. This prevented the building from going cold for several weeks.
Seems like they have found a company than can fix this heating now. But since the complete heating of the community center is a frankenstein-monster, partly enhanced or modernized in differnt decades, with the parts not seeming to be fitted very well to one another, it still might be interesting to see the pattern, how different pumps are activated during the day.
Of course, energy monitoring would be interesting in other aspects as well. I plan on installing some small photovoltaics, too. Since I would have to try to use the solar energy, instead of feeding it into the grid, it would be good, if the big freezer in the basement as well as the water heater could mainly use the electricity during the day and avoid the night as far as possible.
Monitoring the complete house might also make it easier to evaluate the amount of engergy that devices on standby or all those power supplies are wasting.