My sprinkler spills water through PVB when it starts for zone 1 and continues until it is time for zone 2. It works well for zone 2 and the rest. It has been working well for last 8 years until this started two weeks ago. Please help. Thanks. KL
There is a possibility that there is a leak on the first zone, causing low pressure, and a backflow condition. I would inspect the first zone area closely for leaks, that would be your best bet.
