One jar-top valve just WON'T work!

In a newly installed system, one of the Orbit jar-top valves just will not work. I've tried everything I can think of, short of digging it up and replacing the whole thing. I've swapped out ALL the replaceable parts (diaphragm, spring, solenoid, stainless tube) to no avail. I've tested to make sure I have voltage (which I do: about 26 V). Another valve does work. By opening the bleeder screw, water does flow to the sprinkler heads (so I can operate the system manually). Right now, after researching how these sprinkler system valves work, I think the bypass tube/conduit, that is 'opened' by the solenoid, must be plugged. I tried blowing it out with compressed air, but no change.

Before I go to the trouble of digging it up and replacing the valve body, is there anything else I should try? Any other way to clean the small conduit tube when the valve body is in the ground? Anything else that might be causing the problem that I might have overlooked?

Thanks much!

If you have ruled out any electrical problems and have replaced all the parts you have stated, then you are correct thinking the water exhaust passageway is blocked. Take a small piece of 18 guage irrigation wire and push down through the passage way. You should be able to move it freely. Even a small blockage will affect the opening of the valve. I think this will take care of your problem.

Thanks, BRD. I *did* try a piece of wire and an actual pipe cleaner (novel, eh? ;-) too. But, the tube makes a right angle, and is so narrow, I couldn't get the wire to bend around the corner. So, I resorted to digging up the valve and replacing it. That worked! Other than the hassle of trying to get all the pipe back together to patch up the cut, it was pretty straightforward. The pro to the whole thing was adding more gravel beneath the valve to give water a better place to go when draining/bleeding the system.