I am trying to get OpenSprinklerPi up and running and have having some trouble. On my first attempt to turn a zone on, it turned on fine, but would not turn off. I had to unplug the OSPi to turn off the zone. I broke out the multimeter and found the first zone I would turn on measured around -24VDC (I don’t recall the AC measurement, but it was low). When I tried to turn the zone off nothing happened. If I turned a second one on, both would be on, but at a reduced voltage and neither would turn off without unplugging the OSPi. I thought I might have a web app conflict so I tried the opsi_test program. As it cycled through all the zones, it appeared they all were left on. I think this overloaded my AC transformed as it died (hopefully only it).
I believe they are standard AC valves. I honestly haven’t ever paid much attention. When one would fail, I would just replace it with a generate one from Home Depot. Should I have been seeing 24VAC on the outputs of the OSPI rather than -24VDC?