I don't have much experience with solid state relays. I am going to describe my problem.
When I send the signal to the SSR, it activates the valve but if I turn off the signal the valve is still running. I can only turn off the valve by cutting the AC voltage with a switch or disconnecting the voltage source.
I have measured the relay input when I send the signal and when I turn it off. I have not seen anything strange with the oscilloscope.
Can anyone give me some advice?