This has now occured twice. While outside there was a lightning strike in the neighborhood, not sure how close but instantly a valve turned on. I couldn't stop it at the controller. Had to turn the water off to the sprinkler system. Turning the water back on a few days later it would still be open. After a few weeks I was able to turn the water on and the valve worked normal again. Today I had an A/C guy out and he accidentally shorted out something at the a/c unit, not even near the sprinkler valve but that valve came on again right when he threw sparks. I witnessed both events. I had to turn the water off to stop it. Now after he left I turn the water back on and that section continues to run so for now keeping the water off for awhile. I used to be a licensed irrigator in Texas back in the 80's and have done tons of repairs but this has me stumped. I admit I'm not to good with voltage but can't for the life of me figure out why 2 random "votage events" turned on the same section twice now and the valve stays open