Sprinklers come on partially, diagnosis help

Discussion in 'Irrigation' started by Fine Gardens Landscaping, Mar 7, 2013.

  1. Fine Gardens Landscaping

    Fine Gardens Landscaping LawnSite Member
    Messages: 137

    I typically do straight forward repairs. Seeking assistance with a diagnosis query. I have several stations on a system working well. One station doesn't work. The sprinklers on that station only partially pop up. There doesn't seem to be enough pressure there to pop them up all the way. I tested it from the timer and by operating the valve manually with the same result. The house and irrigation system were built about 20 years ago.


    I'm thinking it's pretty much got to be a bad valve, right?

    Or are there some other things I should check? I don't want to charge customer for a valve replacement unless I know for sure that will fix problem. It's a commercial grade valve so I can open it up if there's something I should be checking there.

    Thanks in advance
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  2. garciajj612

    garciajj612 LawnSite Member
    Messages: 115

    The three causes I see the most to heads not popping up: The first would be a leak somewhere on that zone sometimes the leaks are easy to see sometimes they're not. Second, the costumer or the lawn guy switched out the broken nozzles to all 15vans.
    The third, someone could have turned the flow control.

  3. mitchgo

    mitchgo LawnSite Silver Member
    Messages: 2,935

    3 Possible scenarios - Since you are able to turn on the valve from the controller and at the valve manually itself and get the same results.

    1) Easiest thing is Flow control. Check the flow control on the valve to ensure it's just about fully turned up. If the control valve is turned down it will restrict flow. If you don't know what this is please take a pic of our valve and we can help or look up the specs online

    2) The zone has a pipe break that isn't surfacing. Let the zone run for a while and walk the area where the zone is to look for breaks. If nothing you need to turn off all the heads, then utilize the water meter to calculate loss flow. Obviously if all the heads are turned off and the meters running 20gpm ++ you have an issue.

    3) There is a clog / kink in the piping which is typically not the situation because the entire zone is effected.

    Has this zone worked properly in the past? It could be just an over extended zone
  4. Fine Gardens Landscaping

    Fine Gardens Landscaping LawnSite Member
    Messages: 137

    Thx guys

    I checked flow control and it is opened all the way

    It could be a leak that is not obvious. I'm going cap heads and run the zone and check the meter as you suggested

    It had worked properly at one time. There are a couple pop-ups that are leaking some what. Not enough to cause the problem IMO. I can switch over the pop-ups to shrub heads on risers, may look at the reduced flow nozzles.
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  5. 1idejim

    1idejim LawnSite Fanatic
    Messages: 11,288

    1) flow control maybe, manually adjust.
    2) leak maybe, read meter when zone is running.
    3) valve obstruction maybe, read meter when zone is running.

    Where is the valve in relation to the other valves?

    If it is the last valve on the main, you could have an obstruction before the valve.

    If the valve is before the last on the main, look at or after the valve.

    Regardless, eliminate the issues that may be diagnosed with the meter or flow control first.
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  6. Autoflow

    Autoflow LawnSite Member
    Messages: 245

    After checking the other things mentioned you can also add up the flow of the nozzles compared to the other zones. It may have been over stretched when installed or added to. If it has VAN nozzles you can turn some of them off to see if the pressure is increased on the remainder. If you turn some of them off and the pressure increases it is most likely over stretched, but could still be a small leak or obstruction.
  7. AI Inc

    AI Inc LawnSite Fanatic
    Messages: 26,797

    Exactly, you say it worked at one time. Was it struggling then? if it was right on the edge math wise a few weaping seals and a small leak may be killing it.
  8. DanaMac

    DanaMac LawnSite Fanatic
    Messages: 13,209

    My initial thoughts would be a leak that is not surfacing, or pipe is kinked by tree roots.
  9. Mike Leary

    Mike Leary LawnSite Fanatic
    Messages: 23,148

    Based on my limited :)laugh:) experience, I'd say the zone was jacked from the git. If the spinner on the meter is stable, start capping heads.
  10. Flow Control

    Flow Control LawnSite Bronze Member
    Messages: 1,267

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