If the 3 you found are in valve boxes, there's a good chance that the installer placed the other 2 in boxes, too. The box lids may be covered by dirt or thatch, or mulch if they're in a flowerbed.

I use the Progressive Electronics Inc. model 521 valve locator to find valves, but it has always been tricky, especially if your valve wiring is multi-wire...all wires for all valves wrapped in a single casing. In this case, the signal that the locator sends along the wire for the specific valve that you're trying to find ends up bleeding over to other wires, sending you on a wild goose chase around the yard.

You can rent one of these for about $60-70 per day at an irrigation supply house (John Deere Landscapes, Ewing, Wickham, Longhorn, etc.).

Otherwise, go to the zone and keep poking around with a screwdriver in the most likely valve box locactions.
I've seen some less complex/expensive locators that use an electrical signal to make the valve solenoid buzz or click, helping you to locate it by listening. Haven't tried them.

See if you can find a neighbor with a metal detector.

Thanks for the replies, BTW how would a metal detector pick up the valves? Will it be powerful enough to get thru the dirt and the valve boxes to recognize the metal? Just curious..

I have had to search large areas for lost valve boxes where locating equipment was of no benefit. I have had good luck using a thin-tined pitch-fork with five tines about 2.5 inches apart, this is like using five screw drivers at once and enables me to cover large areas quickly. It is also useful to draw a basic drawing of the area showing all the sprikler heads as well as the valves you have located; as this can help you determine where to start searching.
good luck

That is very interesting.. more_to_grow.

How do you use the pitch-forks to locate the valve boxes? could you please eloborate on this process. I would be very intrested in trying this and the metal detector method.

Ram.

If they are metal valves like Champion or Rainbird, they should easily be large enough to find.

Also, even if plastic, they may have metal washers in them and also, the wiring will run to the solenoid which also will have metal in it.

Most modern metal detectors are pretty sensitive and will find buried coins so should be able to spot these items.

I used to have a metal detector and used it many times to find a hitch pin that fell off my tiller almost every time I ran it. Cannot remember how deep it was buried but finding it with the detector was a 5 minute job.

I would not buy or rent a detector but the valves you have found should give you an idea of what type of valve you are looking for and how deep they will be buried.

Thanks for that info. I will find someone who has a metal detector and post a follow-up as to how it goes.

Using the pitchfork to locate your valve boxes is simply a matter of probing, poking, the ground to a depth that you feel will hit the box if it is there. In a mulch bed the box could be under a couple of inches of mulch, in your yard perhaps grass has overgrown the box and covered an inch or two. I have located valve boxes with this method, particularly on golf courses, that have been covered for years and were as much as five inches below grade.

Once you have a plan for where you will search you can work in some logical pattern such that you cover the area completely, the depth to which you probe will find its own based on how hard you push and the consistency of your soil.

Thanks more_to_grow.

I tried the metal detector option and did not have much success with it. I first tested it on the valves that are visible. It was a very feeble response from the Garrett metal detector even with the highest sensitivity. I could not get a good read on it anywhere else. I was able to locate a couple of spots that it identified as Iron. However, could not locate anything there even after making a small hole with a shovel.

I will see if the pitchfork process works. Although, more labor intensive, I think it may have a higher probablity of success.

Now I have something to do for this weekend :-)

I'm having the same problem. i have been over the yard like 10 times and have fo0und nothing. what is the name of this electrical wire finder? it sounds expensive but i have to find the problem. also the reason i have to find it is i think i have a major leak in the yard. and i have no psi coming out of these 4 heads???? i plan to cap them off and run it for like 30 mins and see if i see any wet spots but im sure i will find nothing since i have left it on for 20 mins. and found nothing. the only thing i can think it is, is maybe an old valve is not opening properly? how do i test this valve for operation?

The best way to find them is to use metal detectors. They can detect the things buried underground.

Here is a link that might be useful: metal detectors

y'all,

Unless you know where the valves are there by probability close to the controller to minimize the wire length to the controller. Only in very unusual case of some very large extensive landscaping would group be away from the house perimeter. I have found the probing method to be the best. Usually for buried sprinkler heads and drain boxes not valves. The valves would usually be in a valve box with lid which if buried you will hit pretty easily with a probe. I use a narrow steel soil probe with a tee handle. The main idea is find out how the mainline run out from your source and probe that. The mainline will lead you to the valve boxes. JMHO Aloha