SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

My sprinkler system will not turn on. I had it winterized in October and turned it on now, but it won't come on. I have 2 Toro Flo Pro control valves, which I suspect is where the problem lies. I checked the voltage at the solenoids and both are 24v. The solenoids also work when I turn them on manually (I can see the plungers retract all the way when the solenoids are turned on. I removed the diaphrams, inspected them for tears, etc., and cleaned them both. Now when I turn on the system, I can hear a slight swishing noise at the controllers but the water does not come out of the sprinklers. The diaphrams have 2 white beads on the underside. Do they need to be aligned in a certain position? Do the solenoids need to be fully tightened? When the solenoids retract and release the pressure above the diaphram, where does the air go (is there a vent somewhere)? It looks to me that the pressure is being released only partially by the solenoids, which is causing the diaphram to lift up only slightly; hence the swishing noise. If the pressure is released more, perhaps the diaphram will lift up all the way and the sprinklers would work? Any help would be appreciated.

I checked the water source, it's on. When I unscrew the solenoid a couple of turns, the sprinklers do come on. However, in this position they do not turn off. I think the reason is that when the solenoid is loosened, the air above the diaphram is released and the diaphram lifts up. As a result the sprinklers turn on. The solenoid is supposed to perform this same function I believe (i.e., releasing the air above the diaphram). But, although they do retract, for some reason the air is not being released. Hence my earlier question - is there a vent somewhere through which the air escapes when the solenoid plunger is retracted? Thanks.

Y E E E S S ! ! I was able to get the sprinklers to work (quite by accident). As it turnedout, I didn't have to replace any parts. Here's what I did -

1. The Flo Pro diaphram has two white beads on the underside. When installing the diaphram, I aligned the beads across the flow of water. In this position, they rest on two small shoulders of the water pipe. I guess this prevents the diaphram from being pushed in too far by the spring and getting stuck in the closed position. I couldn't find this alignment requirement anywhere in Toro's documentation.

2. I changed the "O" rings on both solenoids. The rings are seated just above the solenoid threads that screw into the valve jar top cover. The "O" rings I used were slightly thicker than the ones that were already there, and this made the solenoids fit snugly onto the valve and prevented air leaks. I am guessing that the swishing noise I mentioned earlier in the thread was because air was leaking around the "O" rings (although I can't say this for sure).

3. I used teflon tape on the threads when screwing in the valve jar top as well as the solenoid.

Ok, so I got the sprinklers working, but I don't know for sure which of the above steps resolved the issue. The principle of how the valve works is still a mystery to me. E.g., when the solenoid retracts, where does the air escape from? The solenoid is a sealed unit with no ports/vents for the air to escape.

Wet_Boots is right. The next time I have any problems with the valve, I'm going to replace it and save myself the headaches. And, thanks Hi Todd for your help as well.