# Help!! 2 zones in my irrigation system have very low output.



## BigMike (Jun 6, 2020)

Hi All,

My first post. Glad I found you all.

I am in Richardson Texas and my home is on 1/3 acre lot. 11 sprinkler zones. Zones 2 & 7 have very low output. I mean it only sprays 1/6th of what it used to spray and water only reaches a foot or two.most heads don't even popup.. All the other zones are working as normal.

System is ~25 yrs but has been very reliable, only ever had to replace heads. It has Jar Top valves (James Hardie)and I now know this because my son and I dug all day yesterday in 95 deg weather to find the #7 valve. Made my own chatter box with a wall light switch to find general location. The ground around and in the box was dry so no indication of a leak nearby. It is all plumbed with pvc pipe and I know it's at least sched 40, no flex lines.

I watched many many videos on you tube last night on how to troubleshoot them and fix. Here is what I tried so far:

1. My solenoids do not have the rotate to bypass option. I did open the bleed screw but water only came out heads just like normal activation (Weak).

2. I took it apart and cleaned it, Used a straightened paper clip and pushed it thru the tiny hole that goes from solenoid plunger thru diaphragm center hole into main water line to make sure it wasn't clogged. Diaphragm looked a little dirty/sludged due to our N Texas water but nothing broken or damaged or deteriorated and still firm. Honestly, nothing looked wrong inside the valve or with wiring/electrical. Since the bleed screw didn't turn it on full force, I thought it would be a slim chance I could clean it and fix it but tried anyway since I dug a trench the size to bury a body!!

3. I measured 25.3 ac volts at the solenoid from the controller when activated. Measured 25.6 directly at the controller box lugs. .3v drop isn't bad since it is approximately 150 ft run from controller to valve. Cut and rewired connection anyway. All looked good here IMO.

4. I thought I had a broken or crimped feed pipe into the valve but that would mean the water would be running all the time. No water being used at all at the main water meter gauge when zones are all off..

5. I took off 3 or 4 sprinkler heads and only 1 had some debris in it. Others were really clean.

Any ideas what this could be? I'm getting tired of daily hand watering


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## jht3 (Jul 27, 2018)

On #5, did you remove just the nozzle or unthreaded the entire body from the seeing pipe?

When I replaced all the heads in two separate zones this spring I discovered lots of junk in the body and, if they had them, filters. Sand, plasticity crud, even pvc glue. Some of those heads date to the 90s.


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## BigMike (Jun 6, 2020)

I unscrewed the sprinkler nozzle and removed filter. I found some stuff on 1 filter. While the nozzle was off, I started the zone to see if the water would shoot up 6-10 feet like it used to but it only went up a few inches. I figured if there was crud in the body, it would wash out when I did that.


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## BigMike (Jun 6, 2020)

I'm starting to suspect that the pipe is broken/crushed by a root or something between valve and first sprinkler head whichever one that is.... I don't know because the zone goes to 3 areas separated by concrete pool deck. This area would have been modified when the pool was put in 25yrs ago.


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## TSGarp007 (May 22, 2018)

Weird that it is two zones, unless those pipes are near each other and both got damaged.

Old valve already dug up, maybe just replace it and see what output looks like?


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## Slim 1938 (Aug 24, 2019)

Is there a tree nearby? Could it be tree roots possibly choking line somewhere?


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## BigMike (Jun 6, 2020)

Thanks for the replies guys! There is trees in my yard and one trunk about 6ft away from zone 7 valve. When we dug it up there was minimal roots near the valve that was 2ft underground. The roots were not big enough to interfere at all. The zone 1 valve is in front yard 60ft away from zone 7 valve, might not be related. I don't know if both died at the same time, possibly not.

Since the old valve was clean and no damage I suspect it's not the problem at this point plus when I turned OUT the bleed screw, the zone came on but at the same exact rate as when the valve is operated via timer.

I now suspect a broken line on the sprinkler side underground. I have only been running that zone for 5-10 minutes at a time but maybe if I run it for 30-60 minutes, the water will bubble up to the surface or show it's ugly face somewhere.

Too bad there isn't a way to run a camera through the lines to see where there might be a break..... Or.... Is there?


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## Mister Bill (Apr 12, 2019)

BigMike said:


> Thanks for the replies guys! There is trees in my yard and one trunk about 6ft away from zone 7 valve. When we dug it up there was minimal roots near the valve that was 2ft underground. The roots were not big enough to interfere at all. The zone 1 valve is in front yard 60ft away from zone 7 valve, might not be related. I don't know if both died at the same time, possibly not.
> 
> Since the old valve was clean and no damage I suspect it's not the problem at this point plus when I turned OUT the bleed screw, the zone came on but at the same exact rate as when the valve is operated via timer.
> 
> ...


No camera I am aware of, but assuming the valve is working, cap all heads on each problem zone and energize the zones to keep water dynamic pressure on them. It will eventually show the area where it is leaking if it is indeed leaking. If the leak is under a large area of concrete, it may take days before evidence of a leak and locating the leak is much harder. Running new lines for the two zones would probably be best at that point. The surefire way to know if the main line is leaking is to turn the water off to the house, cap all sprinkler heads securely on the affected zones, and observe the water meter. If it is turning, even slightly, you have a leak. If the meter has not moved in an hour, you do not.

With that said, being two zones are acting in the same manner, I would suspect those two mainlines are in the same trench and the culprit is related. Other than doing a bit of troubleshooting as already given, from the first affected head closest to the valve, digging down to and exposing the lateral from the head towards the valve is about the only solution for finding problems like this. But before I did that I would expose the farthest head from the valve and attach a garden hose to the lateral there to see if the affected heads put out proper water flow. If they do, then you know for certain there is a blockage in the main line if there is no evidence of a leak. It's process of elimination.

Edit: I recall a Toro valve that had the same symptom as you are experiencing. I was going to rebuild the valve and when I removed the top to replace the parts, I saw a rock laying in the bottom of the valve body. I removed the rock, reinstalled the valve top, and all was well again. The rock was preventing the diaphragm from moving to full volume when the valve was energized. I would make sure the valve is flowing with absolute certainty before digging up the yard. Temporarily bypassing the valve entirely for trouble shooting would give piece of mind.


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## BigMike (Jun 6, 2020)

Thanks! Lots of good suggestions there.

I forgot to mention that half the lateral lines for this zone are possibly 3-4 ft underground. There was a pool added and fill put in that raised the grade and I'm sure they didn't take the time or $$ to raise the main lateral lines.... Just add longer risers.

I just closed all the outlets best I could by turned the heads screws all the way in and twisting the bubblers to off as well as turning off the micro sprinklers tied to it and removed the soaker hose that goes in narrow strip around banana trees but that's on the surface..

As far as Zone 1 is concerned, I really don't think it's related because it is so far away and in between these bad zones are the Valves for zones 8,9,10,11 in a common location -- Supposedly... since I never dug to find box. I only know that because I had a tech locate them all 15yrs ago when he worked on a different area of the system. I marked my survey with an x where they should be based on his findings..

I am going to let it run for a long time and look at the water meter to see how much flow is happening and then compare flow to a normal working zone...


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## BigMike (Jun 6, 2020)

*Hallelujah!!!*

I just found the leak.

Once all/most outlets were closed off, the water started coming out at a good clip from under the pool deck about 8 ft from the valve. No sprinkler head for another 10 ft but it's a place to start digging.. I know not the best place but the deck is only 3ft wide at that point and can easily be dug out by my strong 16yo son  He's not as excited as I am!!

Thanks for the help guys.


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## Mister Bill (Apr 12, 2019)

BigMike said:


> *Hallelujah!!!*
> 
> I just found the leak.
> 
> ...


Tell your son hard work builds character. :lol: Glad you found the problem and its not too difficult to get to.

Changing the pressure from static to dynamic will usually push the leaking water through the soil. :thumbup:


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