Irrigation Tutorials

Questions about Sprinkler and Drip Irrigation? Free tutorials, articles, FAQs, and reviews. You've found the web's mother lode of irrigation information!

How to Fix a Automatic Irrigation Valve that Won’t Open


The valves are not opening fully because something is blocking the downstream port from the solenoid.  This could have a number of causes.
1. It could be a manufacturing problem.
2. It could be caused by an air bubble in the ports.
3. It could be caused by a port that is partially blocked by dirt.  This would result from not flushing the mainline thoroughly enough prior to installing the valve.

Possible solutions:
1. If you think it is likely #1 return the valve.

2. Activate the valve using the controller.  With the valve running, close and reopen the flow control several times to force any air out.  Valve should work correctly now.  If not, continue…

3a. Turn off the water and remove the solenoid.  Watch for under the solenoid for a o-ring and spring loaded plunger, make sure they don’t fall out of the solenoid when you remove it.  Not all brands have an o-ring and on most the plunger can’t fall out, but be careful anyway.  With the solenoid removed turn on the water slightly, water should squirt out.  Let it run for a while.  Turn off the water and put the solenoid back on.  Turn on the water.  Activate the valve with the controller.  Close the flow control then reopen it a couple of times.  Valve should work correctly now.  If not, continue…

3b. Turn off water, remove solenoid.  Remove the top of the valve, taking care to note how everything fits together.  Watch the springs inside the body.  The valve top has two small ports (water tubes) in it that go from the solenoid through the top.  Blow air through them to make sure they are not blocked.  Use a very small piece of wire to clear them if necessary.  Check for any cracks are rips in the rubber diaphragm.  Reassemble valve.  Valve should work correctly now.  If not, continue…

If it still doesn’t work, return the valve as defective.



If the valve does work when the tester is used, then try cleaning the ends of the wires at both the valve side and the controller side, then remake all of the splices and clean the wire where it connects to the controller also.  Now test using the controller to see if the valve works.  If it does you lucked out, all that was wrong was a bad splice.  If it still doesn’t work then the wires are bad and you need to either replace them or find and repair the broken wire (which is not easy to do.)   Most homeowners opt for just replacing the wires at this point as finding a break or bad section of wire generally involves expensive test equipment.

Custom Search

Ads (not endorsements):