The valves or solenoids as they are known is probably the culprit. It is probably hung open due to sand or a bad seal. As for finding the solenoids yourself it will detail a lot of probing with a rod of some sort. It would be best to call a contractor who specializes in installing sprinkler systems. Ask beforehand if he has a wire tracer or solenoid detector. If he does use him, if he does not he will probably look for the valves as I told you to do, and it will cost you more due to his hours in...
Is there a way to find the lost stuck open solenoid valves that the homeowner does not know where they are? Without spending a lot of money for the tool. Is there a cheaper version of a locator tool? Would a metal detector work to find the valves?
