Low pressure on one sprinkler zone

[mfurey14]

I'm having some trouble with pressure in one my sprinkler zones and I was hoping someone here would be able to help me out. I have 4 zones with Orbit pop up heads on them supplied by a 1 hp Goulds well pump. Zones 1,3, and 4 all work normally and operate around 25 psi. The pump pressure is set up at 40/60. I've replaced the expansion tank, the pressure gauge, the pressure switch, and some of the PVC pipes on the supply side of the pump and the pipes coming right out of the pump. The reason everything looks brown and rusty is because the old expansion tank was leaking and spraying rusty water everywhere. Once zone 2 comes on the pressure drops to about 5 psi and water only comes out of the sprinkler heads in that zone about 5 ft. All heads operate normally and pop up and down fine. My father in law thought it might be the solenoid for that zone, so I replaced it with a brand new one, but it didn't help. The next thing we thought was there's most likely a leak in the line, however I have a city water spigot right next to one of the spigots I have hooked up to the well (I have 5 other spigots hooked up to the well around the house). Normally I just used the city water and hook a hose up from that spigot to the one right next to it for the well pump to prime it. So I thought I'd try and have the city water hooked up this time with zone 2 on and see how it works. When I did that the sprinklers worked like normal at about 25 psi. So because of that I feel like there's not a leak in the line, otherwise even with the city water going through the pump, if there was a leak it still wouldn't work (I would think). Does anyone have any ideas of what could be causing the loss of pressure? I just bought this house last year and this well was already here so I don't know the history of it, I just know the pump is a Goulds J10S. Not sure if it'll help, but I'll post a picture of my pump. I'm also new to all this irrigation stuff and don't know a whole lot of the lingo, so if you could explain anything in easier terms for me to understand I would really appreciate it. Thanks!

 

[johnjh2o]

I would say you have a leak in that zone. It may work with the city water because the city pressure is greater than the pump pressure. With the increased pressure the leak would have less of an effect on the heads.

 

[mfurey14]

If there is a leak whats the best way to find it? I have tried to look for any spots in the lawn with water coming up but don't see anything.

 

[IFIXH20]

I agree with John It does sound like you have a leak in zone 2. You can pull each sprinkler head in zone 2 then plug/cap the adapter ( each head should unscrew from the adapter), Then turn zone 2 on to verify a leak is present - if a leak is present the pump will not turn off. You can also start digging the line up from the last sprinkler head back to the solenoid valve. You should also replace the PVC adapter at the pump with Iron pipe -- transitioning from iron pipe back to PVC to prevent leaks and/or the PVC adpater being blown off the pump.

 

[speedbump]

That makes it unanimous. It's got to be a leak. If the pump didn't drop way down in pressure, then you may have a blockage, but the pump can't keep up with the sprinklers because some of the water is going somewhere it wasn't going before.

 

[AQualityPlumber]

If you need help finding the leak and can't visibly see, you may want to go rent an ultrasonic leak Detector. It's just a probe you stick in the ground. You will turn the pump off. Plug the heads and pressurize the lines. If there is a leak you should be able to hear it and at least you will know where to dig. Good luck.

 

[Lizzie]

Last time I had an issue over the sprinkler pump and its pressure gets decreased day by day and I called a service and they came and checked the pump and said like due to some pressure variation that may cause my pump to leak were I need to stop that leak. At last they help me to stop that and now its pressure came to normal.