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

Congrats on 3000 posts!

So my valves are all on a manifold, would a faulty diaphragm cause thumping?

Since I have 2 types of valves (thanks to the builder installing the front and contractor the back) I replaced one of the thumper valve diaphragms (rainbird) and that did not solve that zone's problems. There was nothing wrong with the old one that I could tell, but the new one did NOT solve the thumps.

Could the backflow be causing the thumps? It has a small crack and needs to be replaced anyway, just working up the nerve to give that a shot.

I guess there could be a leak somewhere. . .

The Rainbird valves are 100DV, I can't seem to spot a flow control bonnet for that model, any idea if they make one or another would work?

I take it the bonnets are interchangeable so I don't have to fully replace the valve, just remove the screws, disconnect the solenoid, and replace.

Replaced one of the troubled zone valves (100DV) with a bonnet from a 100DVF. I turned down the flow until it didn't thump. One of the heads now only sends water 1', the rest are not even covering 1/2 what they did before and leaving a lot of lawn without water. Another oddity, some of the heads were "jumping" up and down, or pulsating up and down.

When the system is thumping, most of the "noise" appears to be coming on the copper side, I barely feel any pulse/thud on the valve, but the backflow looks like it will come off the house! (little exaggeration, but there is vibration)

I think the other suggestion was a leak in the line. I'm guessing I can shut off each sprinkler head then see if I can feel the water running through the valve? Is that the best way to see if there is a leak? Any other ideas?