Here's a few hints on how to find the source of trouble when things wont work. This tutorial deals with arguably the most challenging Do-It-Yourself project in the field of irrigation — namely, troubleshooting. Volumes could be, (and have been) written on electrical troubleshooting alone. Troubleshooting deals more with determining what to fix, than how to fix it. While there are books, seminars, flow-charts, and even videos that deal with the subject, none of these can substitute for experience. This article is no exception. However, with some basic outlines, and common scenarios, we will try to stress the importance of learning “How to think,” as opposed to “What to do.” This concept is the most important lesson a Do-It-Yourselfer can learn as he approaches the task of irrigation system troubleshooting. To "cut to the chase" you can scroll down to the guide itself (Entire System Wont Come On). Years ago, a damn good technician, put it this way as he prodded an employee towards attaining a new perspective: “Remember that everything is doing exactly what it is supposed to do . . . under the present set of circumstances.” Given there are unalterable physical laws that govern both hydraulics and electricity, that statement has to be true. This perspective will allow you to approach your sprinkler system problem from a variety of angles. You know the challenge is to determine which circumstances have been altered that would cause a particular malfunction. When confronted by a particularly difficult, or frustrating troubleshooting scenario, rely on that concept to freshen your approach. Troubleshooting an irrigation system requires a thorough understanding of how each component of the system works, and how each affects the others. Because most irrigation systems consist of two independent subsystems, (low-voltage electrical control system, and high-pressure hydraulic piping/ valve/head system), a Do-It-Yourself troubleshooter needs some familiarity with both electricity and hydraulics. Due to the fact that these two subsystems actually converge and interact at the solenoid control valve, knowledge of the internal valve components and their functions is also beneficial. A capable Do-It-Yourselfer is able to gather information (ie: take readings, perform tests, make visual observations), and then assess the information and interpret his/her findings. Ideally, this process leads to an efficient and timely solution to the problem. Since irrigation systems are underground, and no two irrigation systems are exactly alike (tract-type installations may be an exception), and since few have diagrams or as-built plans, the task of troubleshooting becomes even more challenging. Variations in materials, (pipe/wire), varieties of components (controllers, valves, heads), and the absence of any real standards for installation, tend to complicate the process even more. However, to the seasoned Do-It-Yourself troubleshooter, these factors define the norm. He accepts and even enjoys the challenge, and is never bored with his work. In fact most troubleshooters love their hobby! Indeed, they savor wearing the household hats of electrician, plumber, detective, and ultimately . . . hero! Knowledge and some training are needed in order to be an effective troubleshooter. Proper tools and equipment are also important. Naturally, experience is invaluable. Even with all that, troubleshooting an irrigation system remains an inexact science. Primarily, because the possibility of multiple factors contributing to a single observable symptom complicates the picture. This is why troubleshooting flow-charts, while they are effective training tools and offer some excellent guidance, should not be relied upon too much in the field. Troubleshooting flow charts attempt to illustrate every possible combination of cause and effect, while plotting every possible pathway to every conceivable solution. This tends to confuse somewhat, so respect your troubleshooting flow-chart as a useful tool, don't expect it to provide simple instant solutions automatically. One common category of troubleshooting is that of recognizing inherent inadequacy. That is, In these cases, the landscape will generally reflect the inadequacy of the system. However, depending on how extreme the shortcomings may be, or how much rainfall may have occurred, the situation may not be immediately obvious. The other, and most common, category of troubleshooting would be actual malfunctioning of an otherwise effective sprinkler system. Of course, the malfunction can be as simple as a nozzle missing from a pop-up spray head. For example, the observable symptom: geyser in lawn area while one zone is running; the indicative symptom: overall stress in turf throughout this zone, except one very green wet area near one head. This type of malfunction is a simple one that requires little technical expertise. The observable symptom offers evidence of a quick and easy solution . . . replace the missing nozzle. Let’s talk about a more elusive cause and effect — that of multiple factors contributing to a single observable symptom. Let’s say that we test, observe and inspect your six-zone residential lawn sprinkler system. As we perform the walk-through, by activating and inspecting each station in running mode, we notice a problem on one zone. Zone 4 appears to have very low pressure, (the rotary heads barely pop up and just sort of gurgle water out two or three feet), while zone 1, 2, 3, 5, and 6, (all spray sections), seem to perform properly. The fact that all other zones perform well would eliminate the possibility of a problem at the source, except for one important difference . . . zone 4 is a relatively large section of eight rotary heads, while the rest of the zones are smaller spray sections, consisting of six or eight spray heads each. The larger zone of rotary heads will require more gallons per minute in order to operate properly. So, a partially open valve at the source, (in this case a PVB), could potentially be a factor. Upon investigation, sure enough, the ball valve on the PVB has been partially closed, restricting flow and probably affecting the performance of zone 4. So, we just open the ball valve and write up an invoice, right? Hold your horses! We always re-check after repairs, even if it is obviously remedied now. Uh-oh, it’s a good thing we followed through with that re-check policy, because even though the pressure on zone 4 has improved noticeably, it’s still insufficient! This calls for a more detailed walk-through of the entire zone, closely inspecting each head while the zone is activated, looking for any indication of leakage. Bingo! One of the farthest heads has come loose, (or someone unscrewed it) from the riser. It wasn’t obvious though (no geyser), until we were almost standing on it. Water was just flooding up from under the head, making a huge puddle in the turf, indiscernible from a distance. So after excavating, replacing the stripped riser, and re-installing, as well as backfilling around the rotary head, we are done! Well, except for that final re-test. Upon our final (we thought), re-test we discover that again, while there is a marked and substantial increase in pressure and performance, it is still only about 75% of optimum. It looks like it’s going to be one of those days. Once again we walk the entire section, looking for any indication of additional leakage, and find none. With that possibility eliminated, it is now time to locate control valve 4. So we connect our electronic valve-location transmitter at the controller, trace, locate, and excavate valve 4. Once disassembled, the aged and bloated rubber seal and diaphragm assembly are revealed as the final contributing factors to the poor performance of zone 4. After replacing these worn-out parts, as well as the solenoid, and making new watertight wire splices, it’s time to test again, (before backfilling, of course). This time zone 4 comes on and works like a charm! While the previous scenario may sound contrived, it is actually not uncommon, and it helps to illustrate how there are often multiple factors contributing to poor performance. It stresses the importance of proceeding through such scenarios in a systematic way, eliminating the most obvious factors first, until arriving at the final solution. It also emphasizes the importance of re-testing after completing repairs, and not relying on assumptions. In fact, it would be wise at this point to test the zone on and off several times, in case other heads, unaccustomed to the sudden increase in pressure, should fail. This too, is a common occurrence shortly after such a repair. When troubleshooting the electrical control system, another set of skills and strategies must be utilized. Again, the Do-It-Yourselfer must rely on his knowledge, hopefully some experience, and a systematic approach in order to proceed effectively. Why, then, can irrigation system troubleshooting seem so complicated? To illustrate the intricate interactions of various components and subsystems, we will list some different observable symptom categories, along with related combinations of possible causes. Experience can lead us to consider possibilities, occasionally weighing probability and likelihood against proven facts. This can be helpful if an experienced Do-It-Yourselfer has historical data, or prior knowledge of a particular system. However, troubleshooters as a rule, should resist the temptation to skip steps in their systematic sequence in order to pursue hunches or theories. Think clearly, confirm symptoms, and make assessments and decisions based on your own observations, tests, and solid, proven, troubleshooting methods. Do not allow outside influences or no-it-all neighbors to muddy the waters of clear thought with conjecture. Once again let me emphasize that the most important thing a Do-It-Yourself troubleshooter can learn is “HOW TO THINK” rather than ”WHAT TO DO,” simply because there are too many variables. You have to learn the concepts, not memorize the steps. Do not rely too much on maps to take you where you want to go, because the pathway is constantly changing. Always think systematically, analytically, logically, and deductively. |
