Question
I have a sprinkler system and I am having an issue with Zone 1 not shutting off.  I have 4 zones and zone 1 runs with all of them.  This issue only occurs if zone 1 runs longer than 5 minutes.  I've been told to check the valve but I'm not sure what to look for.  When I open the valve box the only thing I can see to mess with is a black know that looks like it has a plus sign on it.  If this is what I neeed to turn, what direction would I turn it in?

Answer
There should be two knobs on top of the valve.  One is much smaller than the other.  The larger one will be the flow control.  Adjust the flow by opening the flow control all the way (counter-clockwise), then close it all the way, counting the turns.  Then open it back up halfway or a little more.