Question
I installed the Orbit Sunmate 94932 irrigation system with 3 stations and 7 sprinklers about 2 years ago and everything worked fine for a year. The station with 3 heads still works fine but the other 2 stations both have developed a problem. When the system switches them on, there is a rhythmic banging sound and the heads just spirt water every half second but don't pop up. If I manually open and shut the manifold valve, the heads will then come up and work fine till the next time. I have tried to flush out air from the system but cannot seem to solve it. Is is a valve problem do you think?

Answer
Hey David, I hope this helps. It sounds as if your valves are not opening all the way, especially if you can bleed the valve and you have good pressure. It is probably the diaphrams that need to be replaced. Usually diaphrams will last at least 5 years, unless you have cheap valves. It might be wise to just replace the valves with a good quality brand like Rainbird. I would recommend the DVF series from Rainbird. A good website to show how to rebuild or replace a valve is www.irrigationtutorials.com. Good luck and have a great day.