What to Do if a Zone will Not Come on

Let’s say that you discover one area of your yard is drying out. The first thing to do is run your sprinkler system through a complete cycle, either in complete mode or by just manually testing each zone. During this test you find that one zone is not turning on. What now?

If you know which valve controls the zone, and if you know where that valve is, you can go to the valve, turn the solenoid (the thing with the wires coming out the top) about one turn counterclockwise and the water should come on. All this test does is show you have water still coming to the valve, which is reassuring. Turn the solenoid clockwise until it is hand tight and the water stops. Now we begin troubleshooting.

If you don’t know where the valve is or even which one you want, which is the usual case, trouble shooting starts at the controller. A simple test that doesn’t require any special tools is to switch the wire for the bad zone to another position in the controller that you know is good. For example, let’s say zone 4 is the bad zone. All others work. Open the controller so you can see where the wires are connected. It should look something like this:

Switch the wires so the zone 4 valve, which did not run, is now hooked to the zone 3 connector. Now test zone 3 (which is temporarily hooked to zone 4 valve) on the controller. If the zone 4 valve starts working you know you have a controller problem. If it does not then you have either a wiring issue or a problem at the valve. Before we go any further, remember to put the wires back as they originally were.

What if it did start working when you moved it to a different zone? Well, the first thing to do it put it back where it was and try again. It might have been a bad connection. If it still doesn’t work, and you have a zone/screw not being used on your controller, move it to the unused zone. Now test. If it works, great. Now just set the timing on the old Zone 4 to zero and the timing on the new Zone 5 as needed. Just be aware that your controller is getting flaky and may need replacing in the near future. Or it may go for years. You never know.

If you do not have an extra screw you will need to replace the controller.

Now, let’s say that moving the wire did not fix the problem. We now know the problem lies in the wire or in the valve. Unfortunately, the system was put in 10 years ago, landscaping has changed, you are not the original owner of the house and no one has a clue where the valve is. This tends to be the most common scenario.

Now you get to use modern technology to find the valve. Let me say first that most of the tools I mention can be rented, reducing your costs. Some are so useful you’ll probably want to buy and keep. Regardless, these things are simpler to do than they might sound. So off we go…

One way is to use what’s called a Valve Activator.  An example can be found HERE.  It’s called the Pro-48. These are very, very simple to use and will tell you quickly if you have a broken wire or short in the system and will test the clock/controller. Let’s do that first, just to save other wasted steps if it is bad.

First, check the power output from the controller. Turn the controller to the zone you want to test. Turn the Pro 48 off. Connect the red wire to the zone wire and the black to the common. Manually activate the zone. If the proper voltage/current is found the CLOCK 24V AC LED will turn on. If it does, good. If it does not you have a problem in the controller. This usually leads to replacement. Let’s assume it’s good. So now we’ve eliminated the controller in a couple of ways.

Now we need to find the valve. The Pro-48 also has a Chatter feature to help you locate the valve. For Chatter, first TURN OFF the water to the system. This can usually be done at the backflow. Then flip the switch to Chatter and go walk the yard. You should hear a series of clicks coming from your valve. Simply go to the sound and you are there. Remember to turn the water back on when everything is finished. The problem with a Chatterer is the valve may be so deep you cannot hear the click, the wire might be broken or the solenoid might be broken and won’t click. It’s generally more effective on newer systems.

Well, we couldn’t hear the clicks. Now things get more interesting but still far from difficult. At this point you need a WIRE AND VALVE LOCATOR. Again, simple to use.  For general instructions go HERE. Most work the same way. Basically, the wire you are tracing will emit a tone to a receiver. You trace the tone until the valve is located. Sort of like Hot and Cold when you were a kid.

You have now located the valve within a foot or two. If it is not visible use a long screwdriver to probe the area. You should hit the top of the valve box. Most valves are installed in valve boxes for protection. The lids are removable. Looks something like this from the top. It will either lift straight off or will screw off. Either way, it’s what we are looking for. Remove it. You should be looking down at your valve.

Now to troubleshoot. First, put the locator away and re-hook all wires. Look at the solenoid. See the wires coming out of the top? Make sure they are still connected to the underground wires you traced. A loose connection means no valve activity. If they are loose, tighten and test again. If they are not, go to the next step.

The fact that the wire led you here means the wire is good. But good wire does not always translate to good voltage. Disconnect the two wires at the valve. Repeat the test you did at the controller. Turn the controller to the zone you want to test. Turn the Pro 48 off. Connect the red wire to the zone wire and the black to the common. Turn the zone on. If the proper voltage/current is found the CLOCK 24V AC LED will turn on. If it does, good, the wire is good.

If it does not you have a problem in the wire. The insulation might be stripped, causing a short and reducing the voltage to the solenoid. If this is true you probably would have heard a spike in the sound as you traced the wire. You will want to retrace the wire and mark that spot. Then carefully dig up the wire and repair any damage. At this point we’ll assume the wire is good.

So the problem lies in the valve somewhere. First, turn the solenoid (the thing with the wires coming out the top) about one turn counterclockwise and the water should come on. All this test does is show you have water still coming to the valve, which is reassuring. Turn the solenoid clockwise until it is hand tight and the water stops. (yes, you read this earlier in the page. I tend to repeat myself.) If water does not come on this is an indication that either the water flow to the valve has failed or the valve has failed. The usual way the flow would fail is a broken line and you would have walked through a marsh tracing the wire. So let’s assume no broken pipe.

If you can, reconnect the valve and have someone at the controller manually turn on the bad zone while you stand at the valve. You should hear a noticeable click. Try this at least twice if you do not hear something. If you hear a click but no water comes out the valve is bad. If you don’t hear a click then the solenoid, the part with wires coming out, is bad. Either way, one of them needs to be replaced.

Since you are probably working on this by yourself, whip out the handy dandy Pro-48 instead. Disconnect the wires from the valve. Hook the two wires from the solenoid to the Pro-48. It doesn’t make any difference which one goes where. Switch to SOLENOID mode and hit ACTIVATE. You should hear a click and the GOOD LED should turn on. If you do not the solenoid is bad. If it tests GOOD, you have a click and the light comes on, then you have a mechanical failure in the valve. It needs to be repaired or replaced. I want to point out how much was done with the Pro-48. Irrigation repair needs it like a nail needs a hammer.

If the valve has any age on it at all I recommend replacing the entire unit. They are not expensive and you might as well start fresh. On most of them you simply buy the identical model, take off the top of the old and remove any internal parts, put in the same parts from the new valve, close up, reconnect wires and you are done. It’s much easier than you would expect.

The last question is “what if I didn’t locate the valve but the broken wire where the gopher chewed through it?” A little digging should expose both ends of the wire. Splice together with WATERPROOF CONNECTORS, re-hook everything and test the zone. If not fixed, keep tracing until you get to the valve and troublshoot.

For more information about anything involving irrigation, please visit us at www.SprinklerWarehouse.com.