SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I bought this house with the sprinkler system winterized. Spring came, and I started up the system. I have irrigation water coming from 3 large pumps along with a few other small farm houses. The main is 1.5" and comes through a meter. The meter is 100% open and then steps down to 1" and goes into a vacuum breaker. I tested the breaker and I have good pressure on both legs. It then goes into a master valve (1" orbit w/ flow control) and then into a 1.5" poly header that runs about 500 feet (don't know why they stepped it down and back up). 6 valves T off the header at 30 feet intervals each and run numerous rotors. The far end of the header dead ends into 2 control boxes with ( 1" orbit valves with flow control. These valves do not have a manual bleed screw. I went to test the system by opening the main control valve (1" orbit w/ flow control) and all other valves were open. So I had 14 zones trickling all at the same time. I removed the solenoids, cleaned them, diaphragms, and reseated everything. The system worked for a bout 7 days and then all zones started turning on again. I replaced the main valve (diaphragm was in bad shape) and tried again. Still had the same problem. I am at my wits end and I have 2 acres of grass that is drying up. Do the flow control valves need to be tightened a minimum number of turns, mine are full open? Everyone around me has great pressure (3 35+ pumps supplying the water). I have great pressure on the down stream side of the breaker. Why are all my valves opening? They still look clean. I was messing with it today and the system trickled for 45 minutes and then I got great pressure all of a sudden. I watered for a while, turned it back off at the master valve and then had the same problem 1 hour later. This is driving me nuts!!!

And I've totally disconnected the controller and get the same problem.

Found out what it was today. First two valves off the header weren't closing all the way. Shut them off with the flow control knobs and the system is working. Will replace the valves tomorrow since the diaphragms are almost as much as a new valve. Going to add a ball valve upstream of each solenoidal valve when i have the time.