In the late summer this year I had some leaky sprinkler heads. First thing I did was install a shutoff valve at the source of the water. Kind of a pain to manually turn the valve after every watering. The system has 4 zones. I purchased 4 new Toro valves and replaced the diaphragms in the old valves. I noticed there actually was broken PVC in one of the valves that was affecting one of the diaphragms. I thought that did the trick until this week when I noticed a small lake around one of the sprinkler heads.

Can a faulty solenoid keep water flowing to the heads ? Even with the control box set to 'OFF' ?

Should a properly functioning sprinkler head not leak water ? Is a leaky head a sign that the seals in the head are shot ?

Any other ideas appreciated. Thanks.

Edit : searching the web it looks like I need 'check valves'. Are these available for rainbird heads ?

 

I used to work with a guy who installed sprinklers. I don't remember anything about check valves. If you only have one head, with a leak, change the head & see what happens. I have no idea why there was broken PVC, in the line.

 

Sprinkler heads don't seal the water out. If the zone valve leaks..... the water will come out of the head at the lowest point in that zone. The zone valve is electro-mechanical and can leak even with no power. to it.

A check valve won't stop this problem.

 

Which model of Toro valves do you have? Are they antisiphon valves?

And no a sprinkler head should not leak water when the system is shut down. If the controller is OFF, you should not have water coming out of the head at all. At first, I would have thought it was a diaphragm in the valve... Could be that the whole valve needs replacing. Did you replace the whole valves or just the diaphragms?

And you can troubleshoot the solenoid by switching it with one from another zone that is working properly. See how they work on each other. Do you have a multimeter?