SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I have an underground sprinkler system, Rainbird, which was connected to city water and worked fine. I recently had a well drilled which I connected to the sprinkler systerm. All works well, except for the fact that one zone (5 heads) will not shut off. The well and pressure tank cannot run more than one zone at a time. This zone worked fine when I tested it the first time.

I have a total of 8 zones, which are controlled by manifolds in 2 valve boxes. One box is in the front yard, and the other is in the back yard. The front yard box contains a manifold with only 3 valves and the back yard box has a manifold with 4 valves. That's 7 valves for 8 zones.

I manually opened all of the valves and accounted for all of the zones, except for the zone that will not shut off. I'm sure it's just a bad solenoid, which is an easy fix, but where in the heck is that danged valve? I have pretty much ruled out the faulty zone being tied in with another one on the same solenoid.

I called the company that installed the system 15 years ago. They have no schematics or diagrams for me to follow. They said they could use a locater to try to find the missing valve, but it would cost $175 and they cannot guarantee success. They did say that they bored under the driveway to get to the faulty zone, but that's about all they could remember.

I used divining rods to try and locate the valve box and have had no luck. I have located the underground water lines, but I found a curious spot in my driveway that appears to be a repair patch, which is suspiciously close to one of the heads of the faulty zone. Check out the pic and let me know what you guys think. I don't want to bust up concrete if I don't have to, but I have to fix this thing so I can run the system properly.

In the pic, the sprinkler head for the faulty zone is above and just to the left of the spot in the concrete (the spot that's dug out). The water line runs along the edge of the driveway, and the spot in the concrete lines up with where I've located the water line.





Surely, they didn't put a valve under the driveway. Thoughts?

I will definitely look into that, and thank you for your reply, but have you ever seen or heard of an instance where a valve was located under a driveway and covered over with concrete?

I dug down to where I thought the pipe came out from under the driveway and found nothing. However, the pipe that feeds the sprinkler head is about 1 1/2 to 2 ft. deep. I will have to try another approach. I thought maybe I could find the T fitting on that side to see if there were wires running to the valve and I would know which side of the driveway to look for the valve.

Update: It turns out that the line running under the driveway (the one in the pic) is the city water line...lol. I'm still trying to locate the line that feeds that zone, but it's been trying at best. I had a utility locator technician come by today and he found the electrical service to the valve boxes, but I'm still unable to find the valve.

I found the line that feeds that zone. Still no luck finding the valve, though. Although, I was told by 2 different people that sometimes, sprinkler installers will "stack" valves. I've looked in the valve box and still only see 3 valves, and there is approximately 1-2 inches between the bottom of the valve and the dirt. Is it possible that there's another valve upside down in the dirt on the underside of the manifold?