Hello. My sprinkler system has 6 areas/valves that run off a timer. The system is set to run in the middle of the night. This morning when we got up, one area of the sprinklers were still going off. When I tried to turn it off from the timer box, it did not shut them off. We had to shut off the water at the manual valve. We then tried running it from the timer box again and it came on and shut off as controlled. I'm afraid to to turn the auto program back on though. Why would this occur and is there something we should look for? A faulty solenoid?

Thanks!