I have 9 stations in my sprinkler system. Never had thumping until I had to turn house water off recently.

Now have thumping in 3 (1,2,3) of the stations. The others don't thump.

Turned my sprinklers off this morning because thumping is so bothersome.

So I tried what the web suggested I removed sprinkler heads from station 1,2,3 and ran water through those stations for about 5 minutes or so. Shut off the stations and attached sprinkler heads, and tried to water, no luck, still thumping.

This is driving my nuts. How do I fix this?????? Where the main line enters the sprinkler valve boxes there is not an on/off drain valve. I do have a valve to turn the water off to the sprinkler system.

Can someone help me.

Thanks

FYI,
It turns out that the sprinklers are not on their own dedicated line.

It is a hard water line bypassing the water softener and house lines.

I also have 3 on/off water faucets on the sprinkler hard water line. They were installed so I would not have to use soft-water to water the yard.

They have air in them so when I open them while the sprinklers are on the banging stops.

So I let drain for a while but when I turned them off I was still getting banging.

I am having difficulty getting the air out of the hard water line.

Maybe I need a valve installed so I can bleed the air from the line.

Finally, I was able to run a few sprinkler stations without banging.

They will water again on Saturday Morning so I will see what happens.

How do I get air out of that hard water line.

This happened when I turned off the house main water shut off valve so I need to fix this so I can do this.

Easy in the house just open all faucets and flush toilets at highest point no issues.

YOu would have to explain HOW the air would get into a pressurized line in the first place.