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

I have a broken pipe somewhere out front. Moved into a house last summer, just getting around to getting the sprinkler system running. one zone in the front has very low pressure. I've capped the heads I've found, and left the zone 'on'. No water is coming to the surface, but I do see some going down through the drain at the curb. I'm guessing the water has found a path to the drain pipe and not coming to the surface. that zone has four sprinkler heads around the side of the lawn near the walkways. The other zone that covers the front yard has at least 1 sprinkler in the middle of the yard. Assuming they placed the sprinkler heads in the same fashion, there's at least one in the center of the yard that I haven't found yet. Any trick to figuring out the path for the underground pipe?

It's an old system with Nelson (now Signature) valves. No bleed screw. I used a long screwdriver with the tip to the valve and handle to the ear to track down valves stuck open (old trick from troubleshooting tube-type radios). Got the diaphragms changed on a couple of valves. I can hear the water source going pretty good with the 4 heads in the zone capped. Given the water that is making it through the drain, I'm pretty sure it's a leak in a pipe. I may have to just use a shovel and open up the sod near some of the heads.
If I just rely on the auto sprinklers, maybe the grass will start to brown where the leak isn't...

Yep, done that. I think the water leak is close to the drain pipe that flows to the street. I was going to try checking in a line from the drain at the street straight to the house where the gutter downspout is. Might be along that line. A couple of the heads are right on that line also.

Quoted from "Wet_Boots"

Sometimes, you need to cap off the heads in the leaky zone, to get enough water flowing to show itself at the point of the leak.

found it. The sprinkler at the corner of front walk and driveway was connected to a T. one end of the T went under the walk to a very small chunk of dirt under the bay window. The pipe was broken on the house side of the walk under the walk. capped the T heading under the sidewalk, no leak. Whew. I was worried they laid the pipe and then put the walkway over it.