Solid State Relay Either Stuck on or not Running
To make the solution clear in case anyone has this same issue, I was getting some kickback from the inductive load of the solenoid valve. I had been successfully running some 2W solenoid valves with this same solid state relay without issue but then with the larger Gem Sensors 6W valves it turned out that the inductive load was frying the SSR when I turned it off. I'm now running a 1N5819 Diode as a flyback diode to protect from that inductive kickback and the circuit is running just fine. I've included a schematic below, this is my first schematic so let me know if anything is unclear!