How Do I Locate Irrigation Valves and Wires?

Once you’ve determined that you have a problem with certain valves in your automated irrigation system you need to repair them. In order to repair them, you must first find them. This may sound simple but sometimes it’s very difficult to locate valves when the system isn’t running.
Irrigation Valve
Often, your irrigation professional will leave a diagram of your system that shows the location of each valve. If not, you can either have a diagram professionally done or do one yourself. There are many options available to the homeowner when it comes to finding valves, ranging from digging up your entire lawn to using a wire and valve locator. We suggest using a wire and valve locator! Here’s a quick refresher on valves before we go into how to find them.

What Are Irrigation / Lawn Sprinkler System Valves?

Your automated irrigation system has several components, including the programmable controller, pipes, sprinkler heads and system valves. The valves control water flow to the rest of the irrigation system. Each valve handles one area, or zone of your irrigation system.

Automated irrigation systems run by electricity. There are wires running from the programmable controller to each of the system valves. Each valve has a solenoid that gets electric signals from the controller. Finding valves typically requires determining which wire leads to which valve.

There’s a rubber plug, or diaphragm, inside each valve; this diaphragm opens to allow water to flow or closes to shut water flow off depending on the signal the solenoid receives from the controller. If the wiring or solenoid is damaged, the valve fails. While some valves are located above ground, it’s common to put them in a valve box and bury them.

Locating Tips for Underground Valves

  1. There is a method of locating underground valves that is very cost-effective, if done correctly. This method is simply guesswork; by picturing the layout of your irrigation system and determining where the wires from the controller enter the ground, you can imagine the path of the wire. Valves are commonly located near the corners of houses and/or downstream from the backflow preventer. Note: It is illegal in most areas to install underground irrigation valves without a backflow preventer.

Once you think you’ve found the valve, probe to a depth of approximately 6 to 12 inches. If you’ve chosen the correct location, you should hear a hollow sound when your probe contacts the buried valve box. Next, dig around the box being careful not to cut the irrigation pipes or damage the wires.

This method has a potentially expensive downside: If the underground valves are not inside a valve box, probing could cause damage to the system pipes, wires, or the solenoid itself.
Solenoid Activator

  1. Another method of finding valve locations involves going to the city permits department. The installation permit application often includes a blueprint with the location of all the valves in the system.
  1. Yet another way of finding valves is buying or renting a solenoid activator, or “chatter” locator. This tool causes the solenoid to make a noise, or chatter, allowing you to find the valve.

Work with a helper and have them tap the valve wire onto the test post on the irrigation controller. Test every 5 to 10 seconds, listening for click from the solenoid or the sound of water moving through the valve. It’s best to do this at night or early in the morning to minimize background noise.

  1. Another method involves turning on the zone with which you’re working. Pay close attention to which sprinklers pressurize first, as they are the ones closest to the irrigation system valve.
  1. You can also use the valve locator. These tools find lost valves by tracing the wires. Valve locators have a transmitter, receiver, two lead wires and a grounding stake. They transmit a beeping signal through the wire to locate the valves. This is the most accurate way to find valves without damaging your lawn or garden.

Valve and Wire Locator


  1. The Null Principle – Turn on both the transmitter and receiver. While aiming the receiver at the ground, gently sweep the unit from side to side. As you near the wire, you’ll hear a beep. The beep gets louder to the immediate left and right of the wire; however, when the receiver is directly over the wire, there should be almost no sound at all. This “null,” or absence of signal, tells you that you found the wire.
  2. Lawn Irrigation System Valve Location – Using the null principle, start where the system wires enter the ground. As you come upon a valve or solenoid the beep expands covering approximately a 2 to 4 foot diameter area. Typically you won’t detect a signal beyond this area unless the wire leads to other valves in the system. You can always go past the first valve to determine if there are others on that line.
  3. Finding Wire Faults or Damaged Wire – Some locators also detect broken or damaged wires. If the wire is broken, the signal typically stops at the break. If the wire is only damaged, the beep will reduce in volume. Note: Loops of extra wire left underground during installation may cause an increase in signal even if there is no damage to the wires.
  4. Finding the Depth of a Wire – Once you’ve found the path of the wire, mark the ground above it. Now, stand to either the left or the right of the wire and hold the receiver at a 45° angle, pointing towards the wire. Slowly move the receiver to find an angle that returns a null signal; mark that spot. Measure the distance between the two marks and you have the approximate depth of the wire.


If you’re the DIY type and handle maintenance of your automated irrigation system yourself you may find yourself testing irrigation valves for functionality. If you don’t have a valve tester, you can easily make one from three 9-volt batteries. This is a quick and easy project that creates a 27-volt portable valve activator.

How to Create and Use Your Own Portable Valve Activator

  1. Start with three 9-Volt Batteries
  2. Connect them in a series.
  3. Connect one valve wire to the negative pole of your activator.
  4. Connect the other wire to the positive pole which should activate the valve.
  5. If the solenoid is functioning properly you’ll hear a clicking sound.

 NOTE: Be careful when working with batteries. If you damage or short-circuit them, they may leak or rupture.