Well, i'm embarrassed to say I do not have a deep knowledge of the inner workings (yet) of the zone valves......but I did just take apart one of the old valves, (a Richdell) to get a look. This "old" valve looks almost exactly like my new irritol valves I installed in December of 2007, 22 months ago.
There are two sides. One side just unscrews, and inside there is just an o-ring and t small plunger type stopper with a long thin rod that goes into the top that unscrews.
The other side is screwed together with 8 screws. Taking them off and taking off the top part revealed a spring with a long needle going through a diaphragm. On the bottom of that diaphragm there is another round ring of rubber that seats on the bottom body of the valve.
Between them I believe is the solenoid, that screws on. inside that is a small spring loaded plunger. The only difference I can see between my old richdell valve and the new ones is that the solonoid sits higher on the new one, and there is a small "on-off'" lever between the solenoid and the valve body on the new one. This lever does not seem to do anything.
So, my question is, am I correct in assuming I should check the diaphragm on the side that is held together by the 8 screws? If I do not find anything like sand, etc, should I unscrew the other side and check that plunger? Can
I buy from sprinkler warehouse just the diaphragms? Should they go bad in this little time?
Luckily, I installed a sprinkler shut off valve when I installed these valves......they never had one before. When I did all of the plumbing, I was careful not to get any sand/dirt in the line, but I suppose it could have gotten there somehow. I did shut off the sprinkler shutoff, and of course, all rotors stopped leaking.
If you can be so kind now in just telling me if I'm on the right track I'd appreciate it. I just was not sure if you meant the side that unscrews with the plunger, or the real diaphragm unit that was under the eight screws.
I'll check with the sprinkler warehouse for those diaphragms. Thanks again for all the help!!
Frank
"He is no fool who gives up what he cannot keep to gain what he cannot lose"