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Sunday, August 16th 2020, 9:33pm

Brand new valve, brief water leak upon valve closing

Good Afternoon,

Everything seen here is brand new including both valves and all visible pipe. Upon turning the valve on the right off a brief spurt of water comes from the anti-syphon cap and no further leak occurs. I am extremely beginner with irrigation. Is there a simple fix. Is it even worth fixing?

Video here:

Thank you all for your time,




Posts: 2,481

Location: USA


Sunday, August 16th 2020, 9:47pm

I'm not as concerned at the water leaking out the anti-syphon cap as I am the weird noise it makes when it shuts off. Plus it sounds like it has minimal flow going through it. The grunting at the beginning is something those valves do and why I wont install them unless I have to.

Have you bled the air out of the new valves? Open the bleeder screw and get the air out.

Plus check to see that the flow control is turned up far enough. Maybe fiddle with the flow control to see if you can improve the situation.

Is it on a drip line?

Are the sprinklers higher in elevation than the valves?



Posts: 2,481

Location: USA


Monday, August 17th 2020, 12:38am

Ok I'm back. Try this. Take the anti-syphon caps off each valve and switch them. Still have the problem? Is the washer installed on the one making the noise? Is it in crooked?


Supreme Member

Posts: 5,351

Location: Metro NYC


Wednesday, August 19th 2020, 12:11pm

Just as general advice on antisyphon valves, the brief outflow of water at zone shutdown is not an indicator of malfunction. Spring-loaded rotor heads with modern wiper seals are apt to do this sort of thing, as the springs in the heads push water back at the valve. Spray heads have much weaker springs, and don't push back as much.

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