How to Find a Sprinkler Valve

sprinkler valve in flowers
tomsaint/Flickr/CC BY 2.0

Although it may seem straightforward, finding a sprinkler valve in a large yard is a question that arises quite often. For a sprinkler valve repair, the first thing to do is to locate the valve; you might need to dig out the area if necessary. Many sprinkler system installers provide a system diagram that outlines the location of sprinkler heads and valves for the owners, but some do not. Plus, if the sprinkler system was installed by the previous owner of the property, they may not have left you the diagram. Trying to discover the location of a sprinkler valve can be frustrating, but the following tips can guide you through the process.

Some sprinkler valves are installed above ground and thus are easier to locate. These types of sprinkler valves are usually installed near the water source, so the best place to start is by looking around the perimeter of the house. Look behind bushes since shrubbery can sometimes spread as it grows and end up hiding sprinkler valves. Sometimes, however, the sprinkler valves are installed in a valve box that is then buried which can make finding them more difficult.

How to Find A Sprinkler Valve

Estimate the location of the valves by picturing the layout of the sprinkler system. The following methods can help narrow down the location of the sprinkler valve:

  • Note the location of the pressure vacuum breaker or backflow preventer. The backflow preventer will likely be situated near the water source to the sprinkler system. Sometimes sprinkler valves are located close by. If not, the backflow preventer will still serve to provide a starting point for the path of the water lines to the sprinkler valves. If the path of the water line seems clear, try digging a little and follow the path to the sprinkler valve. Be careful not to break the water line when digging!
  • Find the sprinkler controller to serve as the starting point for the path of the sprinkler valve wires. Sometimes tracing the path of the wires can lead to the sprinkler valves. You may need to dig up some of the yard to follow the sprinkler wires, however, but take care not to damage the wires when digging.
  • It may be possible to follow the sound of the water leading to the missing valve. Have someone turn on just that zone at the main controller and listen for water going to the valve. Also, listen for clicking when the valve is activating or hissing from the water pressure in the valve. This is best done when there is little surrounding noise interference.
  • The order in which the sprinklers in that zone start up can be another clue as to the location of the sprinkler valve. Have a helper manually turn on that zone at the controller and observe. The sprinkler head that is closest to the valve should pressurize slightly before the rest of the sprinklers. Start at that sprinkler and try to find the valve nearby.

When you've narrowed down the possible locations, careful probing can be used to find the exact spot of the valve. Use a long screwdriver to probe the ground by going down about 6 to 12 inches. Be careful when probing and go slowly so the probe doesn’t damage the sprinkler valve, water supply valve, or the wiring. If these methods don’t do the trick, you can buy or rent (for a more economical option) a solenoid activator or a valve locator.

Consider drawing up a diagram of the sprinkler system once you have located the sprinkler valves to avoid this problem in the future! It may be a while before you need to repair or replace a sprinkler valve again, and you may not recall the exact location by then.