Zone was running on its own, but why?

I came outside to find a single zone, 10 of 12, running for no reason that I can figure out. I checked the Rachio app and it didn’t show anything running. I quick ran the zone, but it didn’t stop. I had to turn off the water at the backflow to shut it down.

The system has not run a full schedule for a while. I did a quick run of zone 11 this morning to ensure some potted plants I moved would get hit with overspray.

Is this a failed zone valve, something else? Rachio software error? Any ideas?

I am sure glad I was home as that water bill could have been much higher.

Thank you

It certainly can be one of several issues such as what you said: zone, software, hardware, and maybe other things. However, one was to narrow it down quickly would be to disconnect power to the Rachio. If it is still running, you know it is the valve. The most common issue in this circumstance is that the baffle inside the valve is dirty. In other words, depending on the valve, you should be able to take apart the valve, clean it, put it back together, and it works great. This usually can be done without removing the whole valve, just the top.

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Thanks, when the power was off the zone stayed on so I’ll uncover the valve and investigate. I have a round about idea where it is. It’s just covered my grass at the moment.

It’s just odd that it turned on by itself. I didn’t know it could do that. That makes me think it’s more than just a stuck valve.

The diagram on a valve uses the pressure difference on the front side and back side of the valve, plus the solenoid plunger to actuate. If there is a tear in the diaphragm, or debris that would not allow it to seal, then the valve can’t create the negative pressure seal. I would lean towards the diaphragm being an issue, but it also could be a solenoid. I just had to replace one in my yard. I got home to one of my sprinkler zones running at about half pressure. Found the solenoid to be completely blown out the side, and the plunger was stuck partially engaged. I don’t know if it stuck during a run or not.

A crude drawing to somewhat illustrate.


Wow thanks! I’m going to have to delay getting to this for about a week but I will update once I have it located and torn apart.

Thanks again!

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I spent about 4 hours on this today and no resolution. I don’t believe it is the zone box that I was guessing. I opened up the box and manually turned the two valves in it off and the water did not shut off.

It really would be nice if the valves were labeled. I am sure there is some kind of label that would last.

I spent a lot of time trying to find another valve box and was not successful. I scalped the grass, probed, and used my leaf blower in high to move the grass that remained. No luck.

Any other tricks to finding the box? I know the irrigation guys charge by the hour so I don’t need to pay for three hours or so just to find the box if I don’t have to.

A neighbor was looking for valves in his yard and I helped for a bit. We stomped around to listen for the hollow sound, used a probe that was maybe a foot long, dug a bit, and anything else we could think of. He ended having someone with a “wire tracer device” find some of them buried more than a foot down (not sure how that happened). They also found that all of their valves are all in individual small round valve “boxes”, which is not the norm in my opinion. Anyway, I believe the tracer device probably can be rented. It has some kind of transmitter that get hooked on the zone wire(s) and then follow the wire (tone generated by the transmitter) with the receiver.

Well surprisingly I had the same idea and found YouTube videos of using a wire tracer. I bought a tracer an I’m going to trace and probe some more.

Mine are typically surface level, but some are just below it. Sadly many are two valves in a small 4 inch circle box too. Ugh

I’m also the second owner of the home. I have mapped out many of the boxes but not the one I need apparently.

Please let us know how it goes and maybe even the make & model. Others have run into this kind of issue before. I put in our sprinklers, so know where everything goes except for exactly where a single low-voltage line goes that is not used at this time. I did not map out the trenches, but I was lucky enough to find Google has an image of my trenches as historical imagery.

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Well no luck yet. I only found all the boxes I knew of. It did alert to one hidden under a layer of grass, but I did know it was there. I’m going to mow again and then run the dethatcher over it.

I have learned some things, including that I will need to dig up the old box, replumb, and use a bigger box when I need to replace a valve that has two in a box.

Those tracers seem like either around $50 or over $500. Did you go with a less expensive one? Did it work sufficiently well so far? I would like to map out the one set of wires and would consider buying or renting.

It did help me in that I learned how it was wired and understood it now. Since the wires are all bunched together it is hard to trace a single wire just by sound.

I cannot say it has been helpful finding the missing boxes though and tracing the wires leaving one box heading to another did not work. I’m guessing it is a foot underground or more in some areas so that maybe why.

I’m starting to wonder if boxes are under the flower beds. I don’t think they are though as the beds were all put in first and then the irrigation. There are no heads in the flower beds either.

I had success in finding it. First I manually closed all the heads in the broken zone so I could run my other zones.

Headphones was the key to finding it. I took my Harbor Freight wire tracer and taped it to the end of a broomstick. Then I walked around wearing headphones and had very faint beeps. I found two zones this way and possibly one more that is missing.

Pictures of the zone box and broken solenoid. I tried to manually close the zone but that did not work. So I will have to dig up this zone, get a larger box, and plumb in two new valves. No idea why they made it so small and not accessible.

My questions:

  1. Will any valve work? If so is there a preferred or more reliable one to look at or less reliable to stay away from?

  2. While looking at all my valves I notice some of my valves have two of the same colored wires connected and some only have one. The bundle has two of each color and the colors do repeat at the controller. Any idea what is going on there?

  1. Valves: it really is a matter of what you have used and opinion. I have used a few different valves over the years One was from Home Depot and I ended up switching it out for a Hunter. The Home Depot one (I think it was an Orbit) caused a fairly loud water hammer and the Hunter was much better. Since that time, I have stayed with Hunter.
  2. I am not sure that I understand completely. I think all 24VAC valves that I have seen have two wires and probably the same color. With these, it does not matter how they get hooked up, one to the zone wire and the other to the common wire. Wait, are you talking about the bundle of wire going from the controller to the zones? Are you saying you have one bundle at both ends and the colors repeat? In the case of color repeats, sometime both blue, for example, are connected to one valve wire and sometimes one blue, for example, are connected to one valve wire?

Thanks, I just noticed Hunter is what my irrigation company put in last year when I wasn’t able to do it myself.

There are three “connections”: common and then each valve. There are two valves in each box.

Each valve has a connection to the wire bundle and a connection to the common. Some of the connections to the wire bundle has two of the same colors in the connection.

There are two bundles run together . I just see some zones have a single colored wire in the connection and some have a double of the same color wire.

My thought is the extra wire is just part of the a bundle and should be unused but it is used in some. I may need to just wire trace or test. I didn’t take a picture of one of the valve boxes before messing with it. I think it was only connected with one wire but it could have been two.

It is a bit hard for me to tell much with all those wires. If wires are going from one box to another, they might be just spliced together too.

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Ahh that makes a lot more sense than what I said!

Looking at my valves it looks like I just have the normal PGV and not the one with flow control. Would you agree?

Yep! I love the Hunter PGV’s. Easy to find around town, and easy to work on. Are these the ones needing replacement/repair? If so, just buy a new complete valve at a big box store, and scavenge all the guts and top and replace on the existing body. VERY rare for a valve failure to be in the body of the valve. Usually it is diaphragm, crack in the top, or solenoid.


Thanks! I have some of the Hunters on the way.

No, those are the ones that replaced the failed ones last fall. The irrigation company I use sometimes replaced them. No idea what mine are and they are at least 15 years old. Here is the top view of the old ones.

They look like an old Toro valve, possibly a 250/260 series valves. You’ll probably have to go to a local irrigation supply store or order online because they are considered a “commercial” series valve and not a big box store item. New solenoid and diagram kit and you should be good to go. Save the hassle of digging up and replacing the whole valve.

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