Actually yes, it’s set up as a climate component as I needed something I could template, but it’s working well.
Got a bit complex, using an esp32cam in a box pointed at a disassembled Rinnai MC601QA - I then use seven segment OCR to read the temperature of the display and use that as my current temp. I also have some of the outputs of the esp32 connected to a relay board which is wired to the buttons on the Rinnai controller allowing me to simulate pressing the buttons by pulsing the relays.
I’ve set up an automation, so if I change the temp on my climate component, it presses the up or down button until my current temp (read from the screen), matches the desired temp.
Works well, takes a few seconds for the screen feedback loop to be read so not as fast as it could be. But I now have a voice controlled and automated hot water system and have definitely gone too far.