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

Check your water pressure regulator. I have just changed mine and the hammering stopped.

You have to have a plumber install a Hammer valve in the house where the water comes in .And if you want to go one further install a BackFlow Preventer before your sprinkler main valve (gate or Ball valve)

Nestor's Sprinklers & Lighting
Alpharetta,Ga.

www.NestorsLandScape.com

I have exactly what you precribed in a backflow valve before the sprinkler vavles and I still get hammering????

install a backflow and a hammer valve unit ,Home Depot sells them

Which first hammer valve and then backflow or backflow and then hammer valve?

Thank you very much for the help.

If the hammer valve does not seem to fix the problem. More than likely the contractor who installed your system overloaded the zones (to many GPM per zone) Industry standard is water traveling 5 feet per second. Any time you demand more water than what the pipe is sized for, you get water traveling faster that 5 fps. Any thing over 7fps and high water psi will cause hammer when the zone turns on and off.

The way you can prove this is the cause. Have a couple of kids stand on 30% of the heads on one zone so they cannot come up. Have someone else turn on that zone. Listen to the pipes they should not hammer anymore since you are not demanding more than what your water pipes are sized for.

The fix: most controllers have a "jumper" in them that you can allow a 5 second delay between zones turning on and off. This will not allow 2 zones to be on while move from one to another.

You can install smaller nozzles on your heads or split up some zones.

good luck