One channel has poor water output from seven sprinklers. ?Valve ? Underground leak

[MowerMark]

For over ten years my garden has enjoyed automatic sprinklers. Four years ago the controller was changed to an Orbit six channel with remote control. Love it. About two years ago channel four had poor flow. Strange. The valve was fully open. Changed the valve converter & solenoid and the flow was fine. A month ago channel six, not four, which for many years had excellent flow through seven small sprinklers with good grass coverage, developed the new onset of slow flow to all seven half circle and quarter circle sprinklers.

Today the valve and solenoid were changed from an Irritrol 3/4 inch to Orbit (3/4 inch, Model 57029) and despite the new valve being fully open, the slow flow is still evident.

The only troubleshooting step about which I can think is to cap off the seven 1/2" risers and see if there's any flow whatsoever. If there is, there's an underground leak. The old and new valves should not both be malfunctioning. Maybe all seven pop-ups have some debris at the nozzles.

Could the slow flow be the back flow relief valve (or whatever that piece is called) ? That piece and insides were not changed. I did remove the cap and put it back on loosely, then activated the solenoid, let water flow out, then tightened it.

Any other suggestions to fix this ?

 

[MowerMark]

The system took a leak

Thank you for all the suggestions:laughing:

The seven 1/2" risers were capped, and there was still flow from the valves, but no leaking from the risers nor the edges of the lawn. After 15 seconds, water appeared from underground in the center of the lawn.

Diagnosis made!

 

[yardworketc]

Glad we could help you figure it out. Great forum guys!

Dave
Yardwork Etc

 

[motoman]

mower mark, This is to show someone is listening.... I have an 8 line pop up system I inherited when I purchased. Three of the lines have always been anemic with a spray output like a prostate victim. The others are great , putting out big rooster tails. The system is 25 years old. I have never tried to diagnose the weakness, but I will comment on what I have here. Rocky soil so bad you cannot sink a shovel into it. So dig and examine is not appealing. We get 70 inches a year so the exposure (too dry) is only on the front 1/3 acre (no shade which has now died completely with weeds). Anyway the system has a big gate valve shut off about 10" below surface which I turn off and on with the seasons. I have had solenoid feed valves freeze and crack which you probably do not experience? I replaced them.

The 1/3 acre of weeds is now being rototilled. Before flagging the pop-ups I ripped one ,causing the 2" riser pipe to crack. That caused a visible geyser. If you have accidentally stressed a pipe it could be leaking at the ? thread- in connection. Otherwise check for good "grounds" at the individual shut off valves. I suspect bad glue joints in mine which could happen. You are aware probably of the "deburr-prime-fresh glue" discipline needed to get good pvc joints. Anyway I feel your pain . Check output orifices for trapped debris. motoman:thumbsup: