Dear visitor, welcome to SPRINKLER TALK FORUM - You Got Questions, We've Got Answers. If this is your first visit here, please read the Help. It explains how this page works. You must be registered before you can use all the page's features. Please use the registration form, to register here or read more information about the registration process. If you are already registered, please login here.
Make absolutely certain you have the poppets properly centered before the cover is replaced. Unfortunately, their stems are going to be too short to make this a no-brainer.
I checked the flow control - fine
No water splashes out upon shut off.
I will try to ensure poppet is properly centreed, otherwise I guess I will have to expose to line and check for leaks.
You can shut off and/or cap heads to check for leaks, but these poppet failures usually don't leak enough water to kill a zone. If heads aren't working, it won't be the fault of poppets.