Well pump won't hold a prime

Discussion in 'Irrigation' started by mx315, May 28, 2008.

  1. mx315

    mx315 LawnSite Senior Member
    Posts: 394

    I have a new Sta-Rite pump that will hold prime for a few days and then all of a sudden it leaks down and will not shut off. I replaced the check valve about five weeks ago, when I moved the welll pump over about two feet. It worked about four days, then the pump was running when I came out one morning and I had to turn off the breaker. I could hear water run out of the pump back into the main line, so I figured it was a bad check valve. When I removed the old check valve I poured water into it and it leaked through so I was sure that was the problem. I replaced it with another one last week and it's doing the same thing. It has been working fine for about 4 days and I came out this morning and the pump was still running. I turned on the faucet on the outlet line and the water still comes out with good pressure. I turned the breaker off and the water starts running back into the well pipe. I flipped the breaker back on after about a minute and there is no prime again. It's a 2" PVC check valve from Lowe's... maybe a batch is the only thing I can think of.
     
  2. BrandonV

    BrandonV LawnSite Platinum Member
    Posts: 4,169

    problem solved, go to a pluming supply and get a brass foot valve, attach to the end of the line in the well and profit.
     
  3. mx315

    mx315 LawnSite Senior Member
    Posts: 394

    Thanks, that's the only thing I could think of.
     
  4. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,799

    Stop putting the check valve on backwards :)
     
  5. BrandonV

    BrandonV LawnSite Platinum Member
    Posts: 4,169

    touché dirty water
     
  6. Waterit

    Waterit LawnSite Silver Member
    Posts: 2,888

    Trying to figure out the "will not shut off" part. Is it on a tank with a pressure switch?
     
  7. Bigred350

    Bigred350 LawnSite Senior Member
    Posts: 772

    It like Tom said Cut that plastic crap off and put a brass 2" FOOT VALVE on it. I have installed hundereds of them and have hardly had any problems out of them.
     
  8. mx315

    mx315 LawnSite Senior Member
    Posts: 394

    That was the first thing I thought of... because I have done that.

    Waterit, it's on a tank. I haven't installed many of the sta-rite pumps, but the guy at Stovall told me that was common if they drop prime. He even told me that he's seen them vaporize water if it looses prime and runs for a long time.
     
  9. Waterit

    Waterit LawnSite Silver Member
    Posts: 2,888

    It's only common if you have a bad check valve or leaky piping on the well side.

    Oh yeah, I've seen them get so hot the pipe melts.

    I'm going to assume you have a 1-1/2HP centrifugal. We've found over the years that those pumps don't work well with tanks - they simply don't produce enough pressure. If the tank must stay, try this:

    Screw a 2" x 3 " long galvanized nipple into the suction (well) side of the pump, then screw on a BRASS check valve. Screw a 2" PVC male adapter into the check valve and reconnect to the well. Make sure to use pipe dope (NOT TAPE) on your threaded joints. And if you have a union or a T with a plug in it on the well side, get rid of them - they're not necessary and can leak. If you're sucking air you're not sucking water, and you'll lose your prime.

    I'll try to post a pic later of how we pipe pumps up here.
     
  10. mx315

    mx315 LawnSite Senior Member
    Posts: 394

    You're right it's a 1.5HP and the tank doesn't "have" to stay. I just reconnected it the way it was before. I used teflon pipe dope instead of tape and removed the union that was on there after replacing the first check valve. I have noticed that on some pumps, when connecting PVC into the pump inlet, they sometimes will work themselves loose... I guess from vibrations. I was thinking of using the 1.25" galvanized pipe for the inlet side because my outlet side has that for the tank and then connects to the 1" pvc.
    I have been installing the check valve vertical, I'm guessing it's ok to install it horizontal if I'm picturing what you're talking about doing?
    Thanks for the info
     

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