Irrigation system diagnostic help needed

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Old 04-13-15, 12:49 PM
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Irrigation system diagnostic help needed

Hi new member here, this looks like great resource of knowledgeable folks.

Hope I can contribute in the future, but today I have a challenge I need help with.

Problem: low pressure in one sprinkler zone
Situation: mother in laws lake house 2 hours away, father in law (system designer) recently passed, and with him about 95% of the design knowledge.

System has 20+ zones all over with multiple controllers.
Went up to de-winterize and turn on for the season and besides a few minor head fixes needed, all zones are up and running perfectly, except one.

This one problem child powers a few rainbirds and other heads but only had only enough pressure to make 1 of the 5-8 units emit a small 3' stream. Nothing visible from any of the others. Despite letting it run long enough that the water should be showing up, somewhere.

What I've tried so far:

Looked for obvious underground leaks along the presumed path from valve to final head. Found one squishy area where a below ground canister pop-up rainbird was similarly "trickling" but not enough to get it to pop up even the slightest. It was at the edge of the driveway where a tire could run over it so I was thinking broken pipe but there was not enough water there to account for all the running time...

Pulled solenoid off hoping it would run manually and while it did turn on, flow was not improved.

Checked the solenoid and it is being activated by controller, but this particular zone's valve is a different model (Lawn Genie?) than all the others (Rainbird) so its solenoid didn't popout as far as others.

Switched out valve and solenoid for a new Rainbird combo. No change in pressure. Cussed a bit after that failure, had high hopes.

Told my mother in law she was back to hose-watering in that area until I could come up with a better solution...packed up the car and made the two-hour drive home wondering what I'd missed....

SO...anything jump out to you on what I'm missing? Or what I can do to find it?

This is in a small mountain town and there's not a lot (any?) of local irrigation guys around and the few real plumbers up there are booked months out at high $$ rates so I'm on my own.

Hoping someone here can point out the errors of my ways...

Thanks!

(Tried to upload image, keeps failing. Valve is in a box too narrow to turn a wrench, under a low-hanging eave. Great place to swap out valves, fortunately had compression fittings!)
 
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Old 04-13-15, 09:15 PM
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Nothing really "jumps out" at me. My first step would be to change the valve like you did.

Does this zone have about the same amount of heads as the other ok zones ?
Do you have some water trickling out of all the heads ?

You may be trying to upload a picture that is too big. The board limit is 50kb. It will automatically resize somewhat larger pictures but large pics from like a phone would need to be reduced beforehand.
 
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Old 04-14-15, 06:53 AM
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If unscrewing the solenoid did not make that zone turn on then replacing the diaphragm would be next which you took care of by replacing the whole thing. Since you've manually actuated the valve that takes the controls out of it so I'd start looking at water flow issues.

First I would remove the emitter for each device on that zone and check it's filter screen. It's usually in the head and comes off with the emitter. Maybe they are clogged with debris.

If that didn't help I'd remove an emitter. Then turn on the zone. You should have a good garden hose type stream shooting up in the air. If you don't get that I'd start looking for a broken water line or maybe a shutoff valve that's partially closed. To help narrow it down turn off the main shutoff valve for the system and remove the top of the valve for that zone. Then have someone briefly open the main water valve. You should have water gushing out of the disassembled valve. If not then you're problem may be further upstream.
 
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Old 04-14-15, 12:56 PM
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Thanks for ideas...

To try and answer in order...

PJMax -- yes this zone has similar number of heads as all others, and has worked fine for years.
The lowest elevation head is closest to the supply and it is the one that had the 3' trickle stream, one of the highest uphill locations was that below ground pop-up that was overfilling its canister and creating squishy area, but water was not noted in other locations. Thanks for tip on photo size, my phone takes huge pics., will try to resize.

Pilot Dane -- right, removing the solenoid DID make that zone turn on, but just the trickle noted. I thought about then checking the diaphragm for rips but got lazy(?) and changed the whole valve out instead. The valve in question is part of a manifold of 4-6 (I will try again to show you a pic) so it SEEMS like it should have the same water pressure as all others, but I like your idea of a possible half-open shut-off, and testing with the valve top off to verify upstream supply.

I will try that when I go back up next weekend, and also try to resize photo and load as it might be worth 1000 words...

Thanks!

Name:  NoFlow6_png.jpg
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Last edited by SierraDIY; 04-14-15 at 01:08 PM. Reason: Added pic -- culprit valve is #6 far right before I changed it out to a Rainbird
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Old 04-16-15, 05:44 PM
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Problem Solved...

Turns out there was a break in the line below the first riser. Because it was behind a stone retaining wall the excess/leaking water had not yet reached the point where it would be visible on the surface.
Done deal, on to the next challenge.
Thanks to all who contributed brain-power to the problem!
 
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Old 04-16-15, 09:42 PM
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......and thank you for stopping back and letting us know how you made out.
 
 

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