On Monday, May 17, 2021 at 11:02:37 PM UTC-4, Bob F wrote:
On 5/17/2021 4:52 PM, Dean Hoffman wrote:
On Monday, May 17, 2021 at 6:25:21 PM UTC-5, trader_4 wrote:
I have a sprinkler zone valve stuck open, but IDK where the valve box is.
I have two valve boxes, one has 5 zone valves, the other has the main
valve and two zones. Of course the stuck valve is in the box that I
can't remember where it's located. I've tried cycling the valves, listening
for clicks. I can hear clicks in the box I know, but so far despite listening
where I think the other one could be, no luck. No luck with a pitch fork
in the likely spots either. I do have a map I drew when it was put in
25 years ago, but so far I can't find that either.

So any ideas for a cheap way to put a signal on the wires going to it
and tracing it to find it? The wires are probably 8 inches or so deep.
Maybe a rental company? HD? I looked online at Harbor Freight,
they have an AC one, but it relies on AC power. Any chance of
putting something simple and easy on it and trying an AM radio?

I've never tried it. Supposedly, connecting a spark plug wire from a
running vehicle will put a signal into a buried wire. The portable AM
radio will make the most static when it's directly over the wire.
There shouldn't be a return circuit so no current flow to ruin solenoid
valves.

I used a signal generator that would put an audio tone on an AM radio
frequency signal, and used that and an AM radio to get an approximation
of the location of a power cable at my fathers house once.

This gadget from Harbor Freight might help if the wire is close to the
surface.

https://www.youtube.com/watch?v=OyJsXpVZc5E

Update. Doing some more searching, I came across a Chatter Box, which
is a small device you put in series on the valve wire. It turns it on and off
very fast, causing it to chatter so you can better hear it. They go for about $30.
There are also fox and hound signal tracers for finding underground wires that
go for about twice that. Not too bad. Reading about the Chatter Box, it said
to do it with the water off. Which got me thinking, that maybe with no water
pressure the valves make more noise. So I turned off the water. Then I wet
down the rain sensor so that the simple little toggle switch that bypasses it
could be used to easily and quickly turn the zone on and off. I had a helper
work that while I listened again. I immediately heard a clicking right by the
backflow preventer where it exits the house. When checking with the water
on I had heard a thumping there, but it was coming from the backflow device
itself. This click sounds like a valve and very likely is and it was masked by
the sound of the bypass device when the water was on.

It was getting dark, so that's as far as I got. Seems like two possibilities.
One is that where the valve box with the three valves is. Other is that there
are two missing boxes and only the main valve box is in the spot I found.
Only reason I'm skeptical is that it would have been easier to put the valve
box elsewhere, as it would require just one water line run under the driveway
or sidewalk instead of three. On the other hand, I'm pretty sure that I didn't
have more than two boxes. But you'd think I would remember the one right
by the backflow device where I blow it out each year. As they say, we'll see....

Thanks to all for the tips.