Question
Good Afternoon Jeff....
OK, I have a situation that is currently stumping me. Here's the equipment I have first: (1# RainBird ESP Controller #2) PGA 1.5" valves (of which I have four [4] zones). What is happening is no matter what zone is on, I have zone #2 on at the same time. I initially thought I had a defective solenoid. Purchased a new solenoid and installed it. The problem continued. Now I get into it a little deeper. I completely disconnected the two wires leading to the solenoid. Still, the problem continued. I then pulled the top of the PGA valve off and inspected the diaphragm. I found no holes of cracks, but I did find an irregular spot on the sealing surface. Good I thought, that must be what is causing the problem. I purchased a new diaphragm, cleaned everything and installed it. At first, it did not fix the problem (zone #2 still came on with the other 3 zones) I then ran zone #2 by itself, shut it off, and went to the other zones. Finally zone #2 did not come on with the others. I did one more check, ran zone #2 again, and now the same thing....I can't get zone #2 to shut off when any of the other zones are operating. To sum it up, I feel I have eliminated the solenoid as the problem, as well as the controller itself. There is something with the valve that I am not seeing, or just missing. It is such a simple thing, and now with the new diaphragm, I would think I had it fixed...but nooooo. Any thoughts? I'm stumped. Thanks....

Answer
You may have a defective valve body, that is causing the valve to open whenever there is water pressure available.  First though,make sure the valve flow is adjusted. Turn the flow control on top of the valve to full on, then close to full off, then open up halfway. You may also want to dissemble the valve again and check the ports (small openings in the body and top) to make sure they are not obstructed.  Otherwise, consider replacing the valve.