SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

We recently moved into a home with an irrigation system with 11 zones. We had a service come out and get everthing turned up (after winter) and make sure all was in working order. They did replace a valve and/or solenoid but otherwise everything looked good and we've been running it for the past few months. The other day I noticed the water pressure in the shower was low. Upon investigation I could hear water running through the irrigation supply line even though the system was off (it had finished its cycle earlier that morning).

If I turn on the water supply and try to run a zone (any zone), it won't work...the pump runs but no sprinkler heads pop up. If I just leave the water supply on but don't run a zone, there are a couple of zones that dribble water. This makes me suspect there is a valve not shutting. I don't know why, though, several zones would leak and not just one single zone if they all have their own valve. Can anyone shed some light on this?