My lawn sprinkler system has 4 zones and I noticed that one zone is staying on all the time. Even if I set the timer controller to off position, that valve stays on. If I unplug the controller, the valve shuts off. I tried doing a reset on the controller and it made no difference. Do I need to replace the controller?
Turns out the controller is working correctly again after leaving it unplugged for a day. It is possible it went haywire after getting wet from one of the adjacent sprinklers that was misadjusted. I adjusted the sprinkler and put a plastic bag over the controller until I can replace it with a proper outdoor controller model (as the previous owner used an indoor model with no cover.)