My Hardie sprinkler valves are very noisy, like vibrating sound, when they are running. There is some sort of bleeder on the top, and when it is opened, water squirts out. When the water is squirting out, the valve becomes quiet an the flow to the sprinklers is increase. How can I make them work properly

Remove sprinkler head and turn on water to flush system.

Clean heads of any debris and reinstall.

Hope this helps.

Chuck

I'll try it and let you know.

Brett