Every so often a zone will stay on long past its time to have shut down. Many times this is due to the solenoid valve or zone valve being stuck in the "open" position. You try to stop the zone from being "on" by turning the controller to "off" and the zone stays "on". Next, you remove the plug from the controller thinking that it can't get any power and yet the zone stays "on". The problem is hydraulic not electrical. Typically it is because there is dirt and debris in the zone valve preventing it from closing even though the controller has ceased sending a signal for the valve to be "open" or "on" the valve can't physically close. The only way to close down the zone is to shut off the sprinkler main valve.
Continue reading Sprinkler Repairs- Zone Valve Won't Shut Off.
