Do You Have One of These Common Sprinkler Wiring Issues?

Sprinkler Wiring Troubleshooting

Your irrigation system is responsible for keeping your yard beautiful, your plants vibrant, and your lawn healthy and happy. However, getting your irrigation system working can be a headache, and troubleshooting problems can be a difficult, frustrating, and tedious job. This is especially true when the problem isn’t with the plumbing that makes your irrigation system work, but with the wiring.

Your sprinkler system is more than just a series of pipes that carry water where it needs to go—it’s also a series of valves that control water flow, and wiring that controls those valves. So when something stops working, figuring out the problem may seem like a truly overwhelming task. On this blog, our Idaho Falls plumbers will explain a few of the most common wiring faults in your system, including how you can recognize them, and what it takes to repair them.

Faulty Master Valve

Sprinkler and irrigation systems often function off a tree of different valves in order to control different zones. This enables you to water different areas of your property for different amounts of time and even at different times to maximize your control, flexibility, and care. However, each of these valves is secondary to one, singular master valve which controls the water flow to the entire system.

Naturally, when your entire system depends on this one fixture, a fault in that fixture can cause the entire system to go down. There’s a pretty easy way to tell if your master valve is your problem: using an electrical multimeter that measures electrical resistance (a tool available at pretty much every hardware store), run one of the probes to your white common wire, and the other to your master cylinder wire at your sprinkler’s controller. If you’re not seeing any resistance (or infinite resistance) running through that wire, then you have your problem. The fault may be in the wiring to your valve, or with the valve itself, but a few other short checks can help you figure this out. Ideally, you should be seeing resistance numbers between 20 and 60 ohms.

Cut Common Wire

Every valve has two different wires coming from it: a common wire, and a dedicated wire. The common wire is usually white in color and runs from your controller to your master cylinder and then to each of the other valves on your irrigation system in turn. If something happens to cut your common wire, then every valve after the cut will fail to turn on when activated.

If it seems like only one or maybe a select few areas of your irrigation system are turning on, then this is most likely the problem. You can verify this at your controller with a multimeter: place one probe on your white common wire, and the other on each of your other zones. You should see resistance on the areas which are working properly, and then no resistance on the zones after the cut. This is a dead giveaway that something has happened to your common wire between the last working zone and the first inoperative one.

Cut Dedicated Wire

Dedicated wires are wires that runs from your controller to each individual valve, skipping your master cylinder and instead giving you individual control over each area. However, if one area in particular isn’t working, then the problem could be with the dedicated wire that controls it. A multimeter can once again verify this—probe the common wire and then that zone’s dedicated wire and you should see no resistance, with the other areas working just fine.

This could also indicate a problem with your valve itself, however. For example, if the valve itself has gone bad and needs replaced, then you may still see a resistance reading. However, if you see a high resistance reading, such as resistance over 100 ohms, then the valve itself may need to be replaced.