Question
Jim.

I have an older Nelson 8424 watering system that came with the house that we purchased.  Recently the system started acting funny.  I have 3 zones set up.  The sprinkler heads in Zone 3 started to leak water when the system should have been off.  I tried to shut it off at the controller panel but nothing worked so I shut the water off.  I rebooted the system and reprogrammed my settings.  When I turned the water back on zone 3 started up again.

Any advice would be appreciated.  Ron

Answer
Hey Ron, it will either be one of two things, the solenoid or the diaphragm. I would suggest replacing both. Not knowing what valve you have, normally the solenoid will simply unscrew from the body of the valve, and you can screw a new one on and simply re- attach the wires you took off the old one.  to get the diaphragm off, most valves will have screws on the top, and once you unscrew these screws, you can access the diaphragm. Go to www.irrigationtutorials, and this website will give you a better idea on how to rebuild this valve. Good luck and have a great day.