Sprinkler Head problem (last on zone)

Discussion in 'Irrigation' started by bsoneill, Jun 10, 2007.

  1. bsoneill

    bsoneill LawnSite Member
    Posts: 11


    I'm having an issue on one of my zones. The last head doesn't seem to be getting enough water pressure. I tried replacing the head (it's a Hunter i-20) as the first step. That didn't work.

    I also tried turning off several (in fact all) of the other heads on that zone, and still pressure was too low to raise the head. I tried removing the last head entirely and still minimal flow.

    Do I have a leak? Could a rock or something have kinked the line between the last two heads? What should I try now?

    A little history:

    The system was professionally installed about 6 years ago.

    Last year I had my leaching field replaced and the installer hit the line between two spray heads (about three from the end on the zone in question) when they were doing their perk test/deep hole test. This was in early spring (2006) and before the system was opened. I was their and taped the line up so no dirt would get into them. After the field was replaced, I fixed the damaged area myself. I needed to replace about four feet of line. The system worked fine all last summer. So I don't think debris got into the system when the line was ruptured.

    The lines were not driven on with the equipment. They stayed well away from the lines and I didn't need to repair of the grass in that area. As well as the system worked fine last summer.

    Thanks for the suggestions.
  2. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,708

    If all the heads are I-20s you can shut down upstream heads. Or you just might dig up the last working head, and maybe then you could replace the end head with a hose connection, and back-flush the line. That a problem is on a repaired line, is not likely to be a coincidence. Unless, of course, tree roots are causing trouble.
  3. bsoneill

    bsoneill LawnSite Member
    Posts: 11

    Thanks for the suggestion. I did try shutting down all heads and still didn't get enough pressure. I will dig up the last working head and try back flushing the line. I'm guess that something got into the line.

    In thinking I may have a leak, I've let the zone run for 60 minutes with all of the heads turned off and so far, I don't seem to have any wet spots. I just turned it on for another 60 minutes.

    Please keep your suggestions coming.
  4. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    Hopefully you checked the I-20's filter screen to make sure nothing is clogging it up? Rocks, glue debris from a repair upstream, etc.

    What is your I-20 connected to? Swing joint, barbed/ha-ha connection, cut-off riser? A lot of times if debris finally clogs a line it occurs at the junction of the pipe and whatever the sprinkler head is attached to for leveling purposes.

    If you suspect that the last section of the piping is compromised then you can check this out also. Dig up at your last working sprinkler and then cut off the pipe to your problem sprinkler. Run an electrical "fish tape" down it to see it it will go completely through. If there's a clog between this point and the end you then mark the tape, remove it and lay it out on the ground. It will give you an indication as to possibly where a clog might start. However, since this is your last section of pipe it's rare that a clog would occur at a mid-point unless something like root pressure is a contributing factor.
  5. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    BTW... Take pictures. We love a good mystery novel. :)
  6. BPC

    BPC LawnSite Member
    Posts: 119

    The line can be clogged at the point were it reduces. The last head on the zone probably runs on smaller line the head before it. If you can find the point were it reduces I cut that glue point out and check there.
  7. bsoneill

    bsoneill LawnSite Member
    Posts: 11

    Okay. I dug up the last head and the last working head. And attached pictures of both.

    I am not sure what the connection types are called or whether they're the best or not- I thought I had a good installer though. I'm guessing I should pull the last head apart at the first reduction and see if there is debris in the line.


  8. This is very correct. We are constantly tantalized by mysteries, bend over backwards to help with the solution, and then the person disappears with nary a thanks or the answer.:(
  9. I bet there is a small rock in barb elbow, cut flex pipe, unscrew barb fitting from lateral and remove debris.
  10. Uh oh funny pipe. Control yourself purp don't lose it.

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