Hi Paul, I still didn’t get a clear sense of what the power supply issue was. Is it that when you plug in 24VAC, the OpenSprinkler fails to power up? Or is it that it powers up but can’t drive solenoids?
Regarding the two systems, it seems to me that the two systems are not electrically connected (other than perhaps sharing the same transformer?) If so, I am pretty sure there is no issue running both at the same time.