I have a sprinkler system with three zones, I just replaced the valve
for Zone1 as it had cracked, and all three zones worked for about a
week and now when the controller reaches zone3 the heads don't pop up
and it sounds like the water backs up (the copper pipe leading from the
house into the ground shakes quite violently and can no longer hear
running water). I am wondering if this might be most likely caused by
a clog in the sprinkler lines or a problem with the Zone3 valve or
something else. I have opened up the heads on the Zone3 sprinklers and
they are dry. Thank you for any suggestions you might have.