Low water pressure on one zone

[Colin MacKenzie]

4 zones total on a Rainbird system. 2 zones are perfect and my pressure gauge runs at 40psi. 1 zone is not working and no resistance on the solonoid so pretty obvious there. Lastly, zone 2 is releasing some water but very low pressure at a shaky 20psi and can hardly lift a sprinkler head. Pump sounds like it is sucking air as well, but sounds fine and fairly silent on the good zones. This one I am not sure about, so please check my logic.

My guess is since the psi gauge is low the low pressure is not due to obstruction. The gauge is just after the pump and an obstruction would drive the psi higher than usual I think. So this likely means a burst pipe and given that the pressure on the heads is so low and a 1.5HP pump its probably a significant volume. Solonoid is 24v and voltage is good, and pulling the correctly rated 0.5amps. Since another solonoid is gone, possibly this one is too but half working, but I would expect it would behave like an obstruction and psi gauge would be high not low. Am I missing anything?

Given that everything is fine on 2 zones I am not considering the pump, priming or water supply up to the pump to be an issue.

I am highly capable in plumbing and electronics. I can do this stuff and have a lot of diagnostic tools. I have no idea where the the solonoids or piping are other than I know it's not centralized near the pump but each zone solonoid is spread out somewhere in the yard....which is going to be a huge pain to find...so I welcome any cool tricks! (wooden dowsing stick? j/k) Possibly I can just run the zone and then look for a flooded spot on the grass.

Thank you!
Colin

 

[Colin MacKenzie]

Oh. What’d’ya’know went out and found the flood, pipe running under a garden and it’s flooding. That’s solved. Any advice for finding buried solonoids in a large yard though? Haha

 

[Sponsor]

 

[WorthFlorida]

There are a couple of gadgets and I bought the tracer one that you follow the signal but it will not locate a solenoid, only the wire. Doesn't work very well, it easy for the signal to bleed on other wires. One time it did find a cut wire but it was a lot of trail and error and two valves near each other poking the ground. With the signal as you follow the tone, with a poker or pitchfork you stab the ground hoping to hit the valve box. With the toner one clip is on the solenoid wire, the other is wrapping around a screwdriver and stuck in the ground. You do not use the common wire.
Another one is it sends a sine wave down the wire and the solenoid vibrates, but it must be good to hear it.

google "wire locator underground toner" $40 on Amazon. It's ok if you want a challenge, or just call an irrigation company and it'll be found in a few minutes. They usually have the $500 toner kit.

 

[Colin MacKenzie]

Great idea! I've used these tone probes on network cables. Not sure it will detect this wire since I believe the solonoid probably burnt open and none of that cable will be open to the earth to complete a circuit but I will give it a shot. I dug a bunch of gopher holes today. Once I got a lay line I used string to extend the lay line out and used a poker to determine where the corners are. I was tracking the red wires. So I think I am really close to zone 2. Regardless, I can use the tone to find the other 3 zones which will be a big help and easy since there is no break.

So being that you're also from Florida...were your control values spread out like mine instead of all centralized? Did yours have any valve covers? I cant find any and I'm expecting the valve just buried in the beach sand that is my yard.

 

[WorthFlorida]

Our community is on reclaimed water with a separate meter. The lots are relatively small, 45'x115' with four zones. The valves on one side is about 10' from the sidewalk. Next door neighbor's are also nearby. But on the other side the other two were only about 4 feet from the sidewalk. They were found when I had a landscaper cutting sod for new and he hit them. It seems the fours zones installed the valves are around the front corners of the houses. The zones are small and for the two that do the front area I tied the two zones together at the controller. Rainbird can handle two solenoids but I won't trust it with Hunter or Orbit controllers. Back in July I had 1000 sq ft of pavers installed on the one side and about 1/2 of the rear yard and capped off about 15 sprinklers. I now have it programmed for three zones. Zone 1 just four pop ups, zone 2- three pop ups, zone 3- 14 pop ups. When the homes were built the irrigation was tied to the city water so the pressure was much lower. Around 2013 reclaimed water was switched over and the pressure is very high. I usually water for no more than 10-20 minutes per zone.

 

[Fitter30]

Could you use a metal detector?