SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

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

Water is turned back on and everything is operating normally. It is very strange. A/C unit is on the right side of the house, valve in the front, the controller in the garage on the far left corner of the house. The controller was set to "off". I was standing with the A/C guy at the A/C unit when he threw sparks, the sprinkler system immediately came on. I rushed to the controller to verify it was off which it was, the only way to shut off the valve was to turn off the water at the double check valve. When I turned it back on later that day, the valve was still open. I left it off for a few days and now everything is fine again. Same as the day we had lightning in the area. Wiring is good, controller is functioning on all zones. I'm beyond stumped

No I didn't unplug it. It's an old 6 zone Orbit controller, not expandable. I don't see how it can be a controller issue. Controller is on the opposite side of the house as where the A/C unit had a spark event. Section #5 is the only section that came on during both electrical events. The first time it happened I completely took the wires off the controller, both common and the zone wire for that section. Turned the water off, turned it back on a day later and it section still ran when water came on. Left it off for a week and when I turned the water back on the valve was no longer open so I hooked the wires up and tested it and everything worked fine.

The 2nd event the valve stayed open for a couple of days as I tried to turn the water on. After a few days it stayed off when turning water back on and again everything works fine now. Turns on and off as it should during the cycles. It is just plain weird that an A/C spark 50' away from the valve would trigger the valve to turn on and stay on. The a/c breaker is even on the opposite side of the house as the controller. There are 3 valves in the general vacinity as #5, all within 4 feet. #5 is the only one that comes on. I will dig the valve boxes up and check the wiring to all the valves and maybe replace that solenoid but as for what is going on I still don't get it. Even asked some electrician buddies and they didn't know whether to scratch their watch or wind their a$$, LOL