You are not logged in.


Monday, April 23rd 2018, 9:12am

Leaking Anti-Siphon Valve

Hi everyone! First time poster here, thank you for having such a great resource like this.
So I just turned our sprinkler system back on for the Spring/Summer.
At the front of our house we have a below-ground box with 2 Rainbird anti-siphon valves. This box is probably 1 to 1 1/2 feet lower than our backyard on the other side of the property.
One of the valves is connected to the drip system: no issues there, works fine with no leaks.
But the other ASV, connected to the sprinkler system, leaks for 2-3 minutes AFTER the system turns off.
Doesn't leak at all while it's running... leaves about 16-20 oz of water in the bottom of the box that eventually drains away after a few minutes.
Is this normal? Or does that valve need to be repaired/replaced?

Thanks again!



Posts: 2,307

Location: USA


Monday, April 23rd 2018, 1:13pm

The valve isn't leaking, it's draining the line after the valve shuts off.
Anti-syphon valves shouldn't be below grade. They need to be 12" above the highest sprinkler on that line.
You need inline valves and a back flow preventer. Or raise the valves up higher.
Your set up now is a hazard to the cities water supply.

Rate this thread