OK, thanks; problem must be downstream of the problem valve. Funny thing though; it sounds like water is rushing through the problem valve. I left the it (and the master) open for an hour and didn't see any sign of any leak...
But as I said, I replaced the solenoid, verified that it works, and replaced all of the parts in the valve (including the diaphram - I actually tried three different sets of parts including brand new ones). Not a drop comes out of the sprinkler heads, so it's doubtful a line is being pinched. I have no ideas about what to try next.
But is it possible that the master valve fails to work properly <i>only</i> when my problem valve is activated?
I do have one, but if there was a problem with it, wouldn't every other valve be affected?
What does the master valve do basically? I wouldn't know how to begin to troubleshoot...
I had a problem zone. I knew which box fed that zone, but not which valve. So I tried each valve manually - none work. Two of the three zones from that box still work electronically, so I had to disconnect each solenoid and see which one was not activating to determine which was the bad zone (I don't understand why they won't work manually). So I replaced the solenoid on the problem valve only to discover that that circuit was bad. I used the spare wire to that box, and verified that the solenoi...
