New House Irrigation No Water: Backflow Preventer Suspected

New house, irrigation system. Panel box ok, fuse good, battery good. Pro says backflow needs replacement. Valves on but no water. Manual no water. Thinks valve turned off somewhere.

Backflow Can Block All Flow

"A faulty backflow preventer can very well keep water from flowing into your system. Unfortunately, it is very difficult to check them yourself. You need a lot of gauges and training. Since someone specifically told you this is the problem, I would tend to believe them unless there is good reason not to."

Backflow preventers are common failure points on neglected systems. Professional diagnosis with test gauges is standard.