I have five sprinkler zones. Zones two through five are working well. Zone one pressure is so low that the heads don't even pop up. They trickle and flood the immediate area (a few square feet) but that's it.

The first suspicion was a broken pipe. These are normally very easy to find. The water floods to the surface and you can easily spot the problem area. There are no apparent leaks anywhere in the yard. I ran zone one for 20 mins straight and...nothing. I also searched for an unusually green patch. Nothing.

My second suspicion is a bad solenoid. I've never known a solenoid to "sort of" work though. They either work or they don't.

What are the other possible causes of weak sprinkler pressure?

  • 2
    Run the zone and look at the water meter. That should indicate if you have restricted flow (compare to a working zone) or if you have lots of flow and for some reason it's leaking away where you can't find it, or haven't found it, yet, anyway. If you have a "blow-out" connection you could also try hooking up compressed air to see if your leak shows up that way (possibly by ear.)
    – Ecnerwal
    Commented Apr 23, 2022 at 17:08
  • That is a good idea. Thank you.
    – acpilot
    Commented Apr 23, 2022 at 19:03
  • @Ecnerwal - It's a blockage of some kind. The meter is at least 2x faster on other zones. Maybe 3x.
    – acpilot
    Commented Apr 24, 2022 at 3:36
  • when a Blockage is a stone, it usually blocks at an elbow, so check there. Commented Apr 24, 2022 at 9:42
  • The entire zone is low though. Is it likely to be before or after the solenoid?
    – acpilot
    Commented Apr 24, 2022 at 14:52


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