Water from Backflow
(New to the forum - new 6 zone sprinkler system just installed)
When I run any one zone and manually turn off the system everything is fine, the problem happens when I run the Auto-program - All zones work ok and everything does what it should for the right amount of time etc., but when the last zone shuts off, the water starts to "pulse" out of the top of the backflow preventer ( and also small pulses of water come out of every head in all zones). If I turn off the water at the main, the system (BFP) resets and all is good again - until the next auto program completes.
Any ideas would be greatly appreciated