Low pressure on one zone only

Discussion in 'Irrigation / Sprinkler Forum' started by flang1210, Jun 7, 2009.

  1. flang1210

    flang1210 New Member

    Messages:
    6
    One of the 5 zones of my sprinkler system has low water pressure. But when I manuely open the test screw on the valve controlling that zone, the water comes out normally. Any idea please? Thanks!
  2. tomm

    tomm New Member

    Messages:
    41
    solenoid..
  3. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
    Metro NYC
    It can also be a failing diaphragm assembly.
  4. flang1210

    flang1210 New Member

    Messages:
    6
    Thanks guys. I think I found the reason. Somehow when I backed out the solenoid about a turn, the pressure came back on! Apparently the solenoid got screwed too close to the little relieve hole and preventing it from releasing full pressure. Can't explain how it got to be that way after several years working properly.
  5. tomm

    tomm New Member

    Messages:
    41
    Are you in freezing climate? What brand valve are you talking about?

    Some solenoid/plunger assemblies retain water even if blown out/drained.
    When the water freezes it distorts the solenoid/plunger.
  6. flang1210

    flang1210 New Member

    Messages:
    6
    I'm in Houston, pretty warm most of the year. It is Orbit.
  7. flang1210

    flang1210 New Member

    Messages:
    6
    problem in one zone

    Well, this is really puzzling!!!!!Because the solenoid has backed out, it kept leaking, so I replaced the whole top portion of the valve, including new solenoid and diaphram. Guess what??? Still doing the same thing!! It worked when I open the bleed valve manually, but doesn't work the normal way. Yes, the solenoid works because I watched the plunger when I connect the wires. Drives me nuts. Any genius out there?
  8. BRD

    BRD New Member

    Messages:
    53
    Location:
    northeast
    Check to be sure the tiny passageway under the solinoid plunger that connects to the downstream side of the valve is open and not blocked. You can sometimes stick a piece of 18 guage irrigation wire thru it to make sure it is clear. It may have worked initially when you backed off on the solinoid because the water was leaking by the solinoid as you had stated. If the zone is working properly when the bleed screw is opened then I would certainly look at the solinoid and determine if its functioning properly both hydraulically and electrically. The above suggestion would be a easy check.
  9. tomm

    tomm New Member

    Messages:
    41
    I'm thinking BRD nailed this one down. Game over :)
  10. flang1210

    flang1210 New Member

    Messages:
    6
    Thanks! I unscrewed the solenoid and found out the little hole was clear and water was squarting out, I supposed it worked normally? I need to check the voltage into the solenoid and make sure there is enough juice, I think it's 24v. But I need to get a voltmeter first. If the volt is ok, I'll just have to dig up the damn thing and change everything!!
  11. BRD

    BRD New Member

    Messages:
    53
    Location:
    northeast
    If you have'nt already obtained a volt meter, you may be able to do a quick check by placing the hot wire from the faulty zone onto another terminal on the controller and see if that works. Maybe you are not getting enough voltage from the existing terminal on the controller to lift the plunger up sufficiently off its seat . If that does not work you should still check voltage at the solenoid with a meter. Maybe there is something going on with the wiring to the solenoid. Lastly, you said you saw water coming out of the pilot hole when you removed the solenoid. I don't know if you assumed that that meant it was open, but I would take the top part of the valve off ( you said it is all new, so we will assume all is ok with that) . I would then physically check the exhaust port in the body of the valve to make sure it is open all the way through to the exit side of the valve. I had suggested earlier to use a piece of 18 guage irrigation wire or something similar. The wire should push through very easily.The passageway may be partially blocked with grit, sand or the like and that would inhibit the valve from opening. This would be easier then removing the whole valve at this time. Let us know.
  12. flang1210

    flang1210 New Member

    Messages:
    6
    Well BRD, thanks so much for the fantastic idea and it WORKED! The actual plugging was in the bottom part of the valve body in that little hole. I had to do a little push at the wire and it came clear. Put the top part back together and all's well! Really appreciate it!:):):):):
  13. BRD

    BRD New Member

    Messages:
    53
    Location:
    northeast
    Good to hear that you got it up and running and thanks for letting us on the boards know what your end result was. Every thing you were telling us pointed to the solenoid or the small water passages that allow the valve to open. I'm glad you took a second look at that exhaust passage and did not have to pull the whole valve. By the way, it is very seldom in my experience that we have to pull a complete valve, body and all. If those passages are open and the diaphragm seat is in tact, there is not much else to go wrong on that part of the body. Good luck
Similar Threads: pressure zone
Forum Title Date
Irrigation / Sprinkler Forum 5 zone system: one zone has low pressure/spray.. Jun 14, 2014
Irrigation / Sprinkler Forum Low pressure in one zone. Jul 13, 2011
Irrigation / Sprinkler Forum not enough pressure in all zones May 9, 2011
Irrigation / Sprinkler Forum Loss of water pressure in 1 zone Feb 25, 2009
Irrigation / Sprinkler Forum low pressure 1 zone Apr 20, 2008

Share This Page