I have four zones. One zone uses the typical pop-up sprayers for my grass, and the other three are all drip zones for the trees and shrubs. Two zones use Hunter valves, and two are Lawn Genie Rain Jets. All of my schedules run in the middle of the night and very early morning hours.
Last week, I noticed one of the drip zones in my back yard was still running in the middle of the afternoon. The zone had been scheduled to run the night before, so it had obviously been running for about 15 hours at that point. Even though solenoids usually fail in the closed position, I chalked this up to a faulty solenoid and bought a replacement. This happened on one of the Lawn Genie valves.
Then today, I discovered the same thing with a different zone that uses a Hunter valves. It had been scheduled to run last night, and again I found that it was still running in the middle of the afternoon. I ran a quick manual cycle and could feel the solenoid clicking. I know this doesn’t necessarily mean it’s working properly, but in this case it did close the valve like it’s supposed to when the manual cycle ended.
I’m finding the coincidence hard to believe, that two different brands of solenoids both had an abnormal failure in the open position a week apart.
Is it possible that Rachio is not actually sending the signal to close the valve at the end of the zone’s schedule? What else should I be looking for?
9 times out of 10, a zone stuck open is an issue with the diaphragm inside the valve, not a solenoid. It is a probable coincidence that if some gunk got in the line, it is causing the diaphragms to hang open.
Also, while you are correct, a solenoid is a “normally closed” type of devise, the plunger itself can stick, or the little seal on the end can get chewed up causing it to “stick open”.
Regarding the solenoids, I understand they can stick open, it’s just that I think that two solenoids, of different brands and different ages, sticking open in the same week is so improbable as to be the least likely scenario.
Regarding gunk in the line though, is that something that would be expected on a municipal water supply when no plumbing work has been done on the lines? When it happened on the first valve, I did remove the valve top to inspect the diaphragm, but I probably wasn’t paying close attention to whether or not any debris came out when I opened the top to get access to the diaphragm (which looked to be in good shape to me). Would debris/gunk that is large enough to block the diaphragm be easy to see, or can smaller pieces like grit or sand be enough to cause a problem?
Agreed, which is why I don’t think it is the solenoids.
Hard to say. It all depends on where it is jammed up. And, it might not be debris. Depending on your water, just a buildup of hard water can cause the diaphragm to stick. Just removing the top, pulled the diaphram for inspecion could have cleaned it up…
We definitely have hard water here, but again, two different valves of different ages having their diaphragms stick due to mineral buildup seems to be too much of a coincidence.
Are you aware of any instances where a Rachio controller was sending voltage when it was not supposed to? I’m not eager to blame the controller by any means, but it would be helpful to know if that has ever happened before.
I don’t know that it has never happened, but would be a very isolated case if it was.
Typically, when troubleshooting you’d start with the most common and logical fixes. Diaphragm kits are cheap, and take about 5 minutes to replace. Solenoids are a bit more expensive, but also a 5 minute job.
If you want to rule out Rachio throwing rouge voltage, if it happens again, have the multimeter ready and see if there is voltage on the wiring. I’d check at the Rachio pins, and at the valve itself. It isn’t unheard of to have ghost volage in the soil and checking both locations would isolate the source. We are talking tiny milliamps to run a solenoid, so it wouldn’t take much.
That’s basically the plan at this point. I’m going to grab some new irrigation wire nuts and freshen up all of the connections. I’ll also do some voltage testing at the same time. Then I’ll just keep the multimeter at the ready and see if I can catch it in the act.
Thanks for the tip about testing at the pins and at the valves!
