14 of 16 zones do not work
I have a complex irrigation system I inherited when I bought the house. It was working fine for a couple of months but, one day, 14 of 16 zones stopped working. I have:
checked the voltages at the box (Hunter) and they are fine.
put my hand on solenoids when powered and they do vibrate
turned a couple of solenoid several turns counter clockwise but no water comes out.
Between the water main and the system is a vacuum valve (720-A). I don't know how to trouble shoot it.
I do not know the pluming pipe layout but I do have a map of the sprinkler heads.