Sprinkler driving me crazy - valve won't open

[Travelover]

I moved into this house a couple months ago, so I don't know the history of the sprinkler system. It has 12 zones and zones 1 through 11 work great. Zone 12 isn't working. I used A 24 VOLT AC transformer to manually energize the valves to identify which valve controls zone 12. All valves are RainBird brand.

Zone 12 valve:
Won't open when energized directly with 24 volts
Won't open when the solenoid is backed out (unscrewed)
Won't open when the bleeder valve is opened
Solenoid measures 40 ohms, but unscrewing it doesn't make any difference
Has water pressure just like the four next to it in the same box

I checked to make sure the passages are open in the body and the bonnet

Any thoughts on what would keep it from opening?

 

[JPRambo]

try taking the solenoid out(unscrew it) there should be a weep hole that opens the valve - sort of. It should spray water into the air. Some type of trash might have plugged it.

 

[Coyote machine]

try taking the solenoid out(unscrew it) there should be a weep hole that opens the valve - sort of. It should spray water into the air. Some type of trash might have plugged it.

If that doesn't work, then swap out a known good solenoid with #12, if that's feasible.

 

[Travelover]

try taking the solenoid out(unscrew it) there should be a weep hole that opens the valve - sort of. It should spray water into the air. Some type of trash might have plugged it.

Yes, I've done that and the hole is clear as is the small passage to it from the outlet side of the valve body.

If that doesn't work, then swap out a known good solenoid with #12, if that's feasible.

I haven't tried that yet, but the way to manually operate the valve is to unscrew the solenoid 1/4 or more turns. This totally takes the electrical part out of the picture.

I'm starting to wonder if the pipe could be plugged between the controller and the sprinkler heads.

 

[Tractor Seabee]

What is the pipe size? Highly unlikely it is plugged there, would take a lot of junk in the line to do that.

Most installations are a PIA. Most installer obviously do not know what a union is. Trying to cut out and replace a solenoid in those valve boxes (even the biggest ones) is impossible.

I am installing a new system at our place and unions are plentiful. All replacable items can be removed at the unions. PVC unions can be tightnend by hand. I have upstream valve, strainer, back flow preventer, and pressure regulator in the largest box at the beginning of the system, including air vents and drains. Max number of solenoids I can get into the large box comfortably is 4. All low points have drain valves. I gave up on the auto drain valves. I have had solenoids that I could not get the pilot passage cleaned out and had to replace. Good thing they are cheap. That's why the strainer; last thing you want is the BFP passages plugged up. bad enough you have to have them annually tested and certified. Our serving utiliity monitors that stuff closely. Drip systems are really vulnerable to dirt.

All my main lines and solenoids are 1" and every circuit has a loop to equalize pressure on each end. No volume problems.

Ron

 

[ultrarunner]

Had the opposite problem when trouble shooting... the solvent went in so heavy it was like tape and clogged the valve.

Also have had pop up valves plug 100%... the pop up part popped up but no water... did a complete cleaning and all it good.

Are you sure the line has not been capped?

 

[Travelover]

What is the pipe size? Highly unlikely it is plugged there, would take a lot of junk in the line to do that. ................
Ron

It appears to be 1" PVC pipe. I agree it seems unlikely to be plugged unless it was crushed during some other construction, it does go under a driveway with paver stones.

Had the opposite problem when trouble shooting... the solvent went in so heavy it was like tape and clogged the valve.

Also have had pop up valves plug 100%... the pop up part popped up but no water... did a complete cleaning and all it good.

Are you sure the line has not been capped?

I'm not sure of anything...lol. The lady that owned the place was crazy over the landscaping so it seems like she would not allow a zone to die, let alone be taken out of commission. I guess it is possible all the sprinkler heads in that zone are plugged, but seems unlikely. That said, my next move is to dig one up and see if it is open.

 

[Coyote machine]

If I understand what you just said about the under pavers section why not isolate that section by cutting just before where it feeds under the pavers, and see if you have water pressure to there. You can always patch the cut with a coupling....

 

[npalen]

I installed our sprinkler system back in '76 and would hate to guess how many hours I've spent repairing and upgrading since.

 

[Travelover]

If I understand what you just said about the under pavers section why not isolate that section by cutting just before where it feeds under the pavers, and see if you have water pressure to there. You can always patch the cut with a coupling....

What I ended up doing was digging up a sprinkler head and back feeding that whole zone with a garden hose to see what happened. The other five sprinkler heads on that zone worked but no water was back-fed to the sprinkler valve. So, it appears the line is plugged between the valve and the sprinkler heads. Trying to find the closure is just too much work as there are all kinds of landscaping, decks, a new circle drive and the pavered garage apron in the potential pathway. I'm just going to make a convenient place to attach a garden hose to feed the zone and manually water that zone. It is only a few feet from a hose bib.