I have a Rinnai gas hot water system installed with two controllers, I do want to get a third controller for the laundry and ideally do want to get the super dooper expensive (but probably wont because it’s stupidly expensive) bathroom controller for the water cut off feature on filling the bath!
What I am more curious about is the fact it is a proprietary 1-2 wire system with a twin cable (power/data and a ground) running from the heater to the controllers. The controllers are all hooked up in parallel.
What I would ideally like to do is read the current water temperature setting and have it added to my data monitoring of the house. Because it is largely outside of my knowledge I thought I would ask first, but I do have a DSO-nano type hand held oscilloscope that I could add to the line to see what’s coming out of it, but deciphering the values is something that’s beyond me and so I have never even bothered. I would love to have the current value reportable though.