Here are a few common anti-siphon valve models with the valve control features labeled. Most other solenoid valves are very similar in design and use similar controls. The Anti-Siphon Vent is a feature found only on anti-siphon valves.
Additional articles on this website related to anti-siphon valves:
How to Install a Anti-Siphon Valve gives a general overview of anti-siphon valves including situations where they won’t work or will leak, as well as step-by-step installation instructions and troubleshooting problems related to installation.
Q. I have 3 zones for my sprinkler system. I need to remove the valve/pipe/heads from one of the 3 zones in my backyard.
A. You may not even need to turn off the irrigation system water for this project. But it is a good idea to know how to turn it off. You never know when you may need to.
Definition: “Zone valve” when used in irrigation, is the valve that turns on and off a group of sprinkler heads. In most cases the zone valve is an electric activated valve and has a solenoid with wires leading into it on top of the valve. The wires connect the zone valve to the irrigation controller (sometimes called the “timer” or “control box.”) The power to the valve is typically 24 volts AC. It usually will not harm most people if they touch a live wire, but it will give you enough of a shock that you will never want to do it again! Obviously if you have a pacemaker or sensitivity to electrical current you will want to be extra careful around the wires. If you touch your cell phone to a bare wire it may become an expensive paperweight.
Shut off the water. (Optional, if you are not going to remove the zone valve you don’t need to do this.) Turn off the water to the entire sprinkler system. Many sprinkler systems have a main shut off valve that turns off all the water to the sprinkler system. Look around for the shut off valve. It may be in a box underground. Often it it near the location where the pipes enter the house. Often it it in a basement if other water pipes are located in the basement. Once you found a possible shut off valve, turn on one of your sprinkler zone valves so you can see that the system is running. Now try turning off the possible shut-off valve. It the sprinklers stop running you know the valve shuts off water to the sprinkler system. Now check and see if it also turned off the water to the house. If it did, you just found the house main water shut off valve. You may not find a valve that turns off only the sprinkler water. A lot of homeowner installed sprinkler systems don’t have them. You may just have to turn off all the water to the house in order to work on the sprinkler system.
The easiest way is to leave the zone valve installed and not remove it. Just plug it. I’ll tell you how to do that first.
Identify the valve. Now you need to figure out which of the sprinkler zone valves is the one you want to remove. Hopefully you know where the valves are. If not, see the article on how to find missing valves. To determine which valve you want to remove, you manually turn on the zone valves (without using the control box) and see which one turns on the sprinkler you want to remove. On top of your zone valves is a solenoid, written on it you will see ON/OFF arrows. Turn the solenoid in the “ON” direction about 1/4 turn or so. This should open the valve and the sprinklers should come on. Note: Some valves have a lever that turns them on and off, some have a bleed screw you partially turn to make them manually open. Each valve make and model is a little different, so you may have to use some deductive skills to figure out how to manually open your valve. By turning them on one at a time you should be able to determine which valve operates the sprinklers you want to remove. When finished, turn off the valve by by reversing the procedure you used to turn it on. If your valve uses a bleed screw to open it, DO NOT completely remove the bleed screw. Just unscrew it slowly until the valve turns on.
3. Now that you know which valve you want to remove, carefully dig the dirt away from the valve and expose the pipe on the downstream side of the zone valve. If you clear the dirt off the top of the zone valve it should have a flow direction arrow someplace on the valve body that points toward the outlet side. (It may be on the side of the valve, using a small mirror makes it easier to find it.)
Once you know which direction the water flows through the valve, cut out a short section of the pipe right after the valve. Water may squirt out when you make the first cut into the pipe, so be prepared to get some muddy water sprayed at you! A lot of water may drain out when you cut the pipe, depending on how much water was in the pipes and the slope of your yard. You may have to bail water out of the hole with a bucket to remove it. With the pipe section removed you can now use a wrench to unscrew the remaining pipe from the valve outlet. Take the pipe section you removed from the valve (with the threads on it) to a hardware store and buy a threaded plug of the same size and a roll of Teflon tape. Wrap several layers of the Teflon tape sealant onto the threads of the plug and then put the plug into the valve outlet opening. Hand tighten the plug, then use the wrench to tighten it another half turn. Do not overtighten it, if you overtighten the plug the valve body may split open. Now that valve zone is plugged off. You can remove the wires for that valve from the controller if you wish. Now remove any of the pipe or sprinklers you want from that valve zone.
You can remove the entire valve if you want to. I didn’t have you remove the valve because that does not require you to turn off the water to the entire sprinkler system, which is easier for most homeowners to do themselves.
To remove the entire valve: Turn off the water to the entire sprinkler system. Then manually turn ON the valve you want to remove, the sprinklers will come on for a few seconds then slowly shut off as the water discharges from the pipes and the pressure is released. If the sprinklers keep running the water is not shut off! Now follow the directions above. Once the outlet pipe section is cut and removed, cut the wires off the valve, then unscrew and remove the entire valve. Seal the ends of the wires with PVC glue or silicon caulk/sealer if you think you may ever want to use them again. Put a threaded cap on the pipe that formerly connected to the valve.
Removing sprinklers. To remove a sprinkler you can sometimes just grab the top of it and turn it counter-clockwise. It will unscrew from the pipe below it and then you can lift it out of the ground. Often you will need to dig away grass from it so you can twist it out. In most cases you don’t need to dig a big hole around the sprinkler head, just dig away enough dirt and grass to allow you to grip the sprinkler. Fill in the hole with dirt after you remove it. Assuming you are abandoning the pipes, there is no need to cap the pipe off below the sprinkler, just leave it there. If you don’t plan to ever use it, it doesn’t matter if it gets dirt in it.
Removing Pipes. Most of the time we just leave the pipes in the ground. They are a lot of work to remove and most of the time they don’t bother anyone if left buried. If the pipes are not very deep you can often pull them up using “brute force”. Dig down to expose the end of the pipe, grab the end and pull it up out of the ground. If there is thick lawn you may need to cut a slit in the lawn surface to allow the pipe to be pulled up easier. Use a edger to cut the turf directly above the pipe. A string trimmer with heavy string in it may be able to cut the turf. It may use up a lot of string!
I don’t recommend using a vehicle to pull the pipe out, but I know some will try it. If you do this and get yourself injured or killed, you will be featured in those “knuckleheads in the news” columns! If you try attaching a rope to the pipe and the other end to a garden tractor or truck to pull the pipe out of the ground – be very careful. Wear protective clothing, gloves, eye protection and a hard hat. Keep everyone else far away. Have someone there watching from a distance who can call 911 if you get hurt! Here’s why I say you shouldn’t do this: Plastic pipe breaks suddenly and violently when pulled hard. If the pipe or rope breaks while pulling on the pipe both the rope and the pipe can whip around violently and cause injury or damage, ie; break a window. The white hard PVC plastic pipe can shatter and release small, very sharp pieces of plastic that act like shrapnel and cut like dozens of little knives. If the pipe does not come out easily and you see the rope stretching, STOP, it’s going to break! Don’t be an idiot, use common sense and extreme care.
If you can’t pull the pipe up and you absolutely can’t just abandon it in place, the only way I know of to get it out is to dig it out. Ugghh. Lots of work.
Q. I have a drainage pipe for my landscape that is clogged. I tried running a “snake” through it to clean it out, but it wasn’t able to do the job. Any suggestions?
A. I had a similar problem recently, it was with a sewer rather than a drain pipe, but the solutions are similar. My sewers backed up, after trying my short snake and getting nowhere with it I realized it was a major blockage and called a sewer cleaning company.Over the years I have come across a lot of clogged pipes in landscapes. They tend to fall into to categories when it comes to cleaning them out.
Dirt or Debris in the Pipe
When my sewer line backed up I called a sewer cleaning company and they came out and tried to snake it using a metal power snake. A snake is typically the first thing they try, it’s cheaper due to the low cost of the equipment they use, but it doesn’t really do a very good job as I discovered. In my case the standard metal snake would not budge the clog and the snake wound up all twisted up and jammed in the pipe. It took the poor guy a long time to get it out! So they moved up to using a hydraulic cleaning tool (aka hydro-jet, hydraulic flusher, hydro-scrub, etc.) This tool uses extreme high pressure water from a pump that is blasted through several tiny nozzles on the end of a PEX tube. The hydraulic cleaner blasted right though the blockage, plus it really cleaned out the pipe. It costs more than snaking, but it works great. My sewer has a clean-out opening near the street which allowed my to get a look into the pipe before and after the cleaning. After snaking the line using the metal snake there was still a lot of stuff that had built up stuck to the inside of the pipe. After the hydraulic cleaning it was almost completely clean inside. Pretty amazing, I was so impressed I decided to have the guy clean all my sewer pipes with it as a preventive measure. I would never go back to using a snake, next time I’ll just have them start with the hydraulic cleaner. The high pressure water just cuts through stuff. So if your blockage is caused by dirt and debris that has collected in the pipe, you can start with snaking it (you can rent a snake if you want to try it yourself.) If you have someone clean it for you I would just skip snaking it and have it hydraulic cleaned. Hiring a pro to snaking a pipe is generally about $50-100 USD, the hydraulic cleaning runs $150-200 USD. Costs are year 2013 for the Southern California area.
Tree Roots and Crushed Pipes
Sadly, my experience is that often a pipe that does not drain is not a blockage that can be removed with either a snake or a hydraulic cleaner. It is caused by tree roots actually crushing the pipe. If you have big trees in the vicinity of the pipe, this is likely the cause.
What happens is a trees roots create a “Y” where one root goes over the pipe while another passes under it. As the tree roots grow and increase in diameter they squeeze the pipe, they can exert an amazing amount of force! (You’ve probably seen places where tree roots have lifted concrete curbs and sidewalks, so you have seen for yourself how much force a root can exert.) If it is a plastic pipe they will squeeze it until it is flattened and no water can get through. I have seen this many times with PVC irrigation pipes and even with ABS sewer pipes. The corrugated poly drainage pipe often used for landscape drainage pipes, roof drains and sump pumps is very easily crushed. Unfortunately a drain cleaning tool like a snake or hydraulic cleaner can’t fix a crushed pipe. If you know where the pipe runs through the landscape you can use a “fish tape” to find out where the blockage is. if the pipe has an open end you feed the tape in there. If not, yuo may need to cut a section of the pipe out to insert the tape. Just feed the tape into the pipe until it hits the blockage. Now mark the location on the tape where it hit the blockage. Pull the tape out of the pipe and lay it along the known pipe route on top of the ground, with the location you marked at the point you inserted the fish into the pipe. The end of the tape should be in about the same location as the blockage. Dig up the pipe and you will very likely find a bunch of roots and a flattened pipe. Cut out the roots and the bad pipe and replace it. If the roots are large you may need to relocate the pipe so that it goes around them. Do not cut large roots that are close to the trees trunk without consulting an arborist. If you can’t afford an arborist or other landscape expert at least giving it a lot of thought before cutting the roots. Are there sufficient other roots to hold the tree? You can severely weaken the tree and cause it to topple in a wind storm. You might want to consider if it would be advisable to stabilize the tree with cables and stakes if you do cut the roots.
Rainbird’s residential series valves have a small internal filter which can become clogged with grit, even with reasonably clean water supplies. When this filter becomes clogged the valve will no longer fully close when operated automatically. Here’s how to clean the filters.
There are several hand cleaner products made for removing PVC cement/glue from your hands. Most combine a solvent with an abrasive grit and a hand moistening lotion into a single product. The ones I have used work very well. They are typically sold at irrigation supply stores. For some reason I have never seen them sold at the home improvement stores where homeowners tend to buy irrigation supplies.
For the “weekend warrior” who just needs to get the cement/glue off infrequently, acetone will remove it quickly. Be sure to immediately wash any skin you apply acetone to thoroughly with soap and water after getting the glue off. Do not leave acetone on your skin!
Repeated skin exposure to acetone may cause serious health issues, so it should not be used by pros who need to remove glue from their hands often. Be sure to read and follow all precautions on the acetone can.
PVC pipe that is exposed to sunlight should be painted to prevent sunlight from destroying the plastic. But what if you need to repair the PVC pipe later? You can’t glue pipe that has paint on it. In fact, you need to remove all of that paint from the area to be glued, even a small amount may cause leaks in the glued joint.
Using a small brush “paint” acetone onto the area of pipe where you want to remove the paint. (PVC primer will also work as a replacement for acetone, but the purple color makes it hard to make sure all the paint is off.) Allow the acetone to soak in for a few seconds then scrape off the paint with a knife blade or other metal edged tool like a putty knife. If some of the paint doesn’t easily come off re-coat the paint with more acetone. Once most of the paint is off, apply another coat of acetone. This time use a paper towel to wipe off the remaining paint. You may need to wipe down the PVC pipe 2-3 times with fresh paper towels to get a nice clean white surface. Now you can glue your joint using the normal method for gluing PVC pipe as described on the cement/glue can. The acetone will leave the pipe surface feeling sticky, that’s OK, you don’t need to wait for it to dry before you glue the joint. The primary ingredient in the purple PVC primer that is used to clean and prepare PVC pipe for gluing is acetone.
Use caution when working with acetone. Read and follow the warnings on the can. Repeated skin exposure to acetone may be harmful to your health.
Water-proofing your irrigation system’s wire splices is one of the most critical tasks in any installation or repair that involves wire splices. The splices need to be completely water-proof. Taping them up with electrical tape will NOT work for this! The electrical tape will allow water into the splice as it becomes old, brittle, and the adhesive on it dries out. If you don’t water-proof your splices it WILL cause your valve to fail! Don’t save a buck on a wire splice and ruin a $20 valve! I’ll explain in detail why waterproofing is so important later, first let’s get down to the details on how to make a good waterproof wire splice.
General Things That you Need to Know about all splices!
Caution: The methods described below are intended for low-voltage wires of 24VAC or less, such as those used in typical irrigation system controls. They should not be used for higher voltages.
DO NOT BURY SPLICES directly in the ground. Put a box around them to protect them and to help you find the later. A small plastic utility box works fine. Glue a large steel washer to the bottom of the box lid using epoxy. This will allow you to find the box with a metal detector if grass grows over it. Splices are the most likely place a wire will short out in the future, so a box makes the splices easier to find and repair.
2-wire irrigation systems: These are a newer type of system that uses only 2-wires to control all the valves. The irrigation controller sends a signal through the valves to a decoder at each valve. The decoder then allows power to the valve solenoid only when told to by the controller. These types of systems depend on electrical “signals” sent from the controller through the wire to the decoder. Any voltage leak at a splice can severely impact the signal and cause the system to malfunction. For this reason splices for 2-wire systems need to be made much more carefully. Many of the 2-wire manufacturers have specific splice methods they require be used in order to protect your warranty. Be sure to use these if required!
Not sure if your system is 2-wire? As i write this in 2013, 2-wire systems are seldom used on residential systems, but they are also gaining popularity and will probably start showing up soon, first on larger systems. The controller case normally will be clearly labeled as “2-wire”. A 2-wire system will also have a “decoder unit” installed on the wires at each valve. Standard irrigation control systems have two wires going to each valve. But in a standard system one of the wires goes to a single valve and only that valve. So if you have 4 valves there will be 5 wires (1 common shared by all the valves, + 1 individual wire to each of 4 valves = 5 wires.) On a 2-wire system with 54 valves there would be only 2 wires and each valve would have a decoder unit installed on it. The presence of a decoder to be installed at each valve is the best way to tell if it is 2-wire.
The best way to make the splice is to use special water-proof splice connectors that you can buy at any hardware store. These are made for sealing outdoor wire connections and work very well. There are many different styles and types available.
Water-Proof Twist On Connectors – “Nut” Style or “Wing” Style
Most of the connectors currently used by pros consist of an twist on type wire connector that is filled with a water sealing grease. Sometimes these are called water-proof “nut” or “wing type” connectors. These are inexpensive and very simple to use. Here are general instructions for use since a lot of these inexpensive connectors are sold without instructions. If instructions came with the connectors please use those instructions, as they are intended for the actual connectors you bought!
For every 3 connections you need buy 5 connectors. Why? Because you will probably make several bad splices, and you will have to remove those connectors and toss them in the trash. They can’t be reused because when you remove them a lot of the sealer comes out with the wire. (If you look close most connectors actually say “do not reuse” or similar language on them.)
Start by stripping the insulation off the end of the wires to expose the bare metal wire. Do not strip off too much insulation, the exposed bare wire should be about 1/2 the length of the connector body. You can splice 3 wires together easily using a single connector. It’s OK to put 4 or 5 wires in a connector, but be warned that it gets a lot more difficult getting the wires to stay in the connector when you use more than 3 wires.
Place the bare ends in one hand and using your other hand, align the wires side-by-side, so the ends of the bare sections are lined up together. Those ends need to all go into the connector together at the same time, so hold the wires tight and don’t let them slip out of position. Do not try to insert an additional wire into a wire connector that already has wires spliced together in it. You need to remove all the wires and redo the splice to add more wires.
Push the connector down over the bare ends of the wire. Twist the connector clockwise to screw it on. Hold the wires firmly in position as you twist the connector over them. The connector has threads, a spring, or barbs inside it that will grab the wires and cinch them together tightly as you twist it on. Stop twisting when you feel substantial resistance.
Hold the connector in one hand and tug on each of the wires with the other to make sure the wires are secure and will not pull out. If a wire feels loose or pulls out, disassemble the entire splice and try again. Use a new connector as some of the sealer will probably be lost when you remove the connector, and it needs all the sealer for a good seal. If the wires still pull out after another try you are probably using the wrong size connector.
Finally make a visual inspection of the splice. The insulation on the wire should be fully inserted into the sealer gel or grease. No bare wire should be visible. That’s all there is to using twist on wire connectors, they are very quick and easy.
The connector size is important when using twist on connectors! Be sure you buy and use the correct size connector for the wire sizes you are splicing. The package will list the various wire size combinations that the connector works on. The connector colors indicate the connector’s size and most are standardized. Here are some general guidelines. Warning: There are some brands that do not follow these color guidelines so double check the instructions on the package!
Connectors for #18 wire. Most residential irrigation systems use #18 size wire, this is the size of most of the multi-wire underground irrigation cables sold in hardware stores. Unfortunately the colors for these connectors are not standardized. Most I have seen are dark blue or black. Make sure it says it will connect 2- #18 wires.
Connectors for #14 & #12 wire. Larger irrigation systems and commercial irrigation often use individual #14 wires. Sometimes #12 will be used for irrigation systems with very long distances between the controller and the valve. Most often these connectors are yellow. Note: Most of the yellow connectors I have seen will NOT connect a single #14 wire to a typical valve solenoid wire. For this you will probably need the smaller #18 wire connectors above.
Mechanical Clip Style Non-Stripping Connectors
Clip style is a catch-all name I use for the various types of connectors that use a mechanical clamping system to grab and bite into the wire. Typically with this type of connector you push the wire into a round slot on the connector, and then squeeze some type of clamp that bites into the wire to hold it in place. Some require pliers to squeeze the clamp into the wires. The most popular of these types of connectors for irrigation use is the Blazing Snaploc BVS Series wire connectors and the 3M Scotchlok 314 series connectors. These connectors are more expensive but make a very secure connection almost always on the first attempt. You won’t need to buy nearly as many extras for bad splices.
Container Type Connectors
These connectors are a two piece, two step system. You connect the wires together using either a standard twist type wire connector, a crimp sleeve, or even soldering the wires together. Then you shove the splice into a container filled with a water-proofing grease or jell and snap a retainer lid closed to hold the splice inside the container.
A variation on this type of connector is the original waterproofing method used back when I started in the business. You mixed a 2-part epoxy resin in a small plastic envelope and then shoved the splice into the envelope so it was covered in resin. The resin was allowed to harden creating a solid water-proof seal. Unfortunately the resin was a carcinogen. I don’t think these are sold any longer.
Q. My irrigation pump runs fine when the system is operating, but after it turns off it cycles on for 5 seconds every 10 minutes or so.
A. If you are using a pressure switch and pressure tank to turn the pump on and off my first guess would be that you have a water leak in your irrigation system. The water leaks out, which cause the water pressure to drop, then the pump kicks on and recharges the pressure. Then the pump shuts off again. That would cause exactly this symptom.
Knowing the problem is the easy part. Finding the leak, that could be harder to do. It could be a zone valve that isn’t turning off all the way or it could be a leaky pipe. You can narrow the search area a little, the leak will be someplace in the pressurized part of the system, that is, between the pump and the zone control valves. Start by looking for obvious dripping, then look for someplace that seems wetter than it should. If it is a leaky zone valve then the water will be leaking through the valve into the sprinkler zone pipes and will dribble out at the lowest sprinkler head. So look at the sprinkler heads. There will be a small “swampy” area around the lowest sprinkler head that is controlled by that valve.
If the valve won’t open at all, or doesn’t fully open, start with the obvious things just to be certain. I know, any idiot knows better, but even us pros periodically overlook something really simple and obvious.
Tip: There are labeled photos of some of the more popular valve models showing the various valve controls (such as flow-controls, on/off levers, and bleed screws) mentioned in this article at this page: Anti-Siphon Valves with Parts Labeled.
Is the water supply turned on?
Is there a shut off valve on the water supply that may have been closed? Once I had a system I couldn’t get to work, couldn’t find any closed valves, but still no water to the sprinklers. Turned out the city water company had closed a valve in the street for street work they were doing and forgot to reopen it!
Check the flow control on the valve to make sure it isn’t closed or partially closed. It is often desirable for the flow control to be left partially closed, but if it is restricting the flow too much that could be the problem. On some valves the flow control doesn’t have a handle, it is just a small screw in the valve lid. If unsure, look up your valve model at the manufacturer’s website to see if they have a drawing of the valve showing a flow control device location. Unfortunately, some inexpensive valves do not have a flow control device.
Manual Operation Test
Try manually opening the valve, using the on/off lever on top of the valve body. Some valves use a bleed screw to manually open them, so if you don’t see a lever labeled on/off or open/close, look for a screw, typically the screw has a knob handle to allow it to be twisted by hand. Do not fully remove a bleed screw! Just turn it about 1-2 to 1 full turn, water will squirt out from under the screw and the valve should open. Some valves have both a bleed screw and a on/off lever, on those valves I generally use the bleed screw as I have found it works better if the valve is being stubborn. If the valve opens correctly and fully when using the manual open lever or bleed screw, then the problem may be electrical. If the valve does not open fully when using the manual open feature, skip over the next section on electrical problems.
Now use your actuator to test your solenoid and wires:
NOTE: make sure you are using fresh, brand new batteries in your actuator! It takes a lot of amperage to open a valve and worn or old batteries won’t do the job. Don’t waste your time tracking down false results caused by bad batteries!!!
Note #2: 24 VAC does not feel good if you shock yourself with it, especially if you are wet. Don’t touch bare wires without rubber gloves on!
Disconnect the wires from the valve solenoid. Touch the valve solenoid wires to the terminals on your activator. The valve should open. If the valve fully opens then the problem is NOT the valve, the problem is with the wires leading from the controller (timer) to the valve, or possibly the controller is broken. Continue with the next step. If the valve does not open, then skip the rest of the electrical diagnosis items. The problem is with the valve or the valve solenoid.
Controller problems are very rare, it is much more likely the problem is a broken wire. Do NOT try to test the controller by using a wire to create a short-circuit “spark” between the terminals! You may fry your controller! First reread the controller manual on how to wire the valve circuits and make sure you don’t have them wired wrong. Optional: You can test the controller using a multimeter if you have one and know how to use it. The controller output to the valves is 24 VAC. Most modern controllers will show a positive test for 24VAC even if the circuit is off, you need to test the circuit with a load. Don’t panic if you don’t know what that means or don’t have a multimeter. Just go to the next step.
You can test the wire very simply. If the wires from the controller to the valve are disconnected from the valve reattach them to the valve solenoid now.
Next remove the wires for the common and the “lead” wire circuit to your valve from the controller terminals.
Attach your valve actuator to the 2 wires at the controller end, just like you did to the solenoid wires. The valve should come on. If it doesn’t open, or only opens partially, the wires from the controller to the valve are either damaged (cut or short circuiting), or you are testing the wrong wires. Are you sure you have the correct pair of wires for this valve? That’s often the problem with a newly installed system! It’s pretty easy to get the wires mixed up, especially if they do not have color-coded insulation. Another source of the problem may be damaged insulation on the buried wire. If the insulation on the wire has been removed or damaged someplace along the length of the wire it can cause a voltage leak. A nick or partial cut in the wire may cause resistance to the current in the wire. These wire problems cause the solenoid to not receive sufficient power to fully open the valve.
If the valve does turn on fully the problem is the controller. Most modern controllers are not user repairable. If it is under warranty contact the manufacturer for instructions. They may ask you to do some additional tests. If the controller is not still under warranty you can contact a professional irrigation repair outfit for a repair quote. For most low-cost homeowner controllers it is cheaper to just replace the controller with a new one. If your current controller is not a Smart Controller you should consider replacing it with one. A self-adjusting Smart Controller will save you a lot of water and effort.
Valve Cleaning and Repair
If you’ve tested the controller and wires and they are OK, then the problem is with the valve itself. You have two choices: remove and replace the valve, or disassemble the valve to look for problems. Which way you go depends on which is easier for you to do. I generally try to clean the valve rather than replace it at this point.
Replacing a valve: Removing and replacing a valve can be a big job if the valve is fully installed. Basically this is a swap out, take a photo of the old valve before you remove it, then remove it and install the new one in it’s place. You probably will need to cut the pipe on the outlet side of the valve so you can turn the valve body to unscrew it from the inlet pipe and get it out. Some valves are installed so close together that you need to cut the pipe on both the inlet and outlet sides, this is especially true of anti-siphon valves. Once the old valve is out, you install a new one in the same location. Finally you need to repair the pipe if you cut it. If the pipe is PVC they make special couplers for repairing pipes that make the job easier. Remember to completely water proof all the wire splices!
Note: a lot of anti-siphon valves are not properly installed. Even sprinkler installation companies don’t use the care they should to insure correct installation, and a incorrect installation may be the source of your valve problems. See the article on How to Properly Install an Anti-Siphon Valve to help you get it in right this time!
Clean & Repair a Valve: Most people try to repair the valve rather than replace it. I really think a repair is often easier at this stage. If you do proceed with disassembling the valve be sure to notice how all the parts fit together so you can reassemble it when done. Tip: take photos of the valve and how the parts fit together as you disassemble it!
If the valve is more than a couple years old you might want to purchase a repair kit for the valve make and model (see bottom of this page for examples of what to look for.)
Turn off the water supply to the valve. Remove the solenoid by unscrewing it. Note: each manufacturer’s valve is slightly different, but the basics are the same. Your valve may look different from the Water-Master brand valve shown in these photos.
The bottom of the solenoid has a spring-loaded plunger in it. After removing the solenoid hold it in one hand and press the plunger in with your little finger. The plunger should spring back out when you release it and move freely in and out without catching or jamming as you press on it. If it doesn’t the solenoid is defective, see the manufacturer’s warranty info for how to proceed with replacement. If the solenoid is fine clean the bottom of the solenoid with a clean towel.
Next clean the little socket area in the valve lid that the solenoid screws into and make sure there aren’t any sand grains or bits of plastic loose in that area. Using compressed air (that canned air used to dust computer parts works great, some people can blow sufficient air with their mouths using a drinking straw…) gently blow air toward the ports (tiny holes) in the bottom of the solenoid socket. Keep the air outlet a couple inches away from the ports. Do not place the end of the air outlet against the ports! If you jam the air outlet down on them and blast air from a can or air compressor into the valve you will burst the rubber valve diaphragm inside the valve!!! You just want to gently blow any loose debris out of the ports and socket. Now screw the solenoid back on hand tight. Do not over-tighten it, do NOT use a wrench. It has a seal so you don’t need to crank on it to keep it from leaking. If you over-tighten the solenoid and force it too far in it will distort the plastic and the plunger will jam. Now with the solenoid back on, don’t bother to rewire it yet. Turn on the water and check to see if the valve works manually. Sometimes the solenoids aren’t installed correctly and this is all it takes to fix the problem. If the valve now works rewire it and you’re done. If the valve still doesn’t work go to step 2.
Remove the solenoid again. Now remove the valve’s lid or cap. The lid or cap may screw off like a jar lid, or it may be held in place with screws. If it is the jar lid type you may need a strap wrench to remove the lid. (They market these jar lids as “easy to remove”, I’ve found few of them actually are.)
A rubber diaphragm sits under the cap and there is a spring between it and the cap, watch for the spring that it doesn’t get lost. Be very careful not to let dirt get into the valve body while the cap is off, put a piece of kitchen cellophane wrap or something similar over it to keep out dirt.
Once the cap is removed look at the cap. There are tiny holes, called ports, that go from under the solenoid to the bottom side of the cap/lid. Make sure none of those ports are blocked by a bit of manufacturing plastic or dirt. You can use a tiny piece of wire to clean them, be very careful not to scratch the plastic or enlarge the hole. Sometimes one of the ports is not drilled all the way through. In that case the valve is defective, see your warranty information for how to replace the valve. I have known people who have successfully used a tiny drill bit held in their hand to very carefully drill a blocked port clean. If you are very careful this may work, BUT it may void your valve’s warranty! One guy had 6 valves all with the same partially drilled port, clearly a manufacturing error. He drilled them by hand and every one of them worked afterward. Your call on that one.
The lid or the diaphragm may also have s small screen filter built into it. Look carefully they are small and hard to see. This is a feature found primarily on a few more expensive brands. At the time I am writing this most Rainbird valves have a tiny filter molded into the diaphragm, so if it is a Rainbird valve be sure to look for it. If there is a screen be sure it isn’t clogged up. A toothbrush works good for cleaning the screens.
Check the rubber diaphragm for any cracks, tears, rips, or holes in it. It should be flexible and in very good condition. If not, replace it. Repair kits with replacement diaphragms are sold at some hardware stores, all irrigation stores, or may be obtained online.
Reassemble the valve when you are finished cleaning the parts and checking for blocked ports. Everything goes back in the same place it came from. Be very careful not to get dirt into the valve when reassembling it. Lubricate all the o-rings using standard KY Jelly (not the heating/stimulation types.) Do not use oil or silicone lubricants! KY Jelly is water-based and will not destroy the rubber seals like oil based products will.
It should work correctly now.
Ads for Typical Repair Parts:
(Amazon has lots more repair parts, for many brands, this is just a start! Hardware & home improvement stores in some areas also carry valve repair parts for a few common models. Dedicated irrigation stores usually stock common brand parts and can order just about any brand or model.)
See the glossary on my web page for an explanation of any words or
terms used below that you don’t know. Example; if your not sure what
the difference between a lateral pipe and a mainline is, look up
those words. https://www.irrigationtutorials.com/glossary.htm
Check the valves to be sure they are fully opening. First, make sure
the flow control setting (if there is one) on the valve is in the
full open position. Next, manually open the valve using the bleed
screw or the open/close lever on the valve. Does the sprinkler
system work better? If so either the valve is bad, the controller is
bad, or the wires are bad.
Get three of the standard box-shaped 9 volt radio batteries (the ones
with the snap connections on the top). Make a “battery chain” by
snapping all three of them together end-to-end. This gives you 27
volts (9×3) between the unattached end terminals. That’s enough to
power the valve. Disconnect the valve wires at the point where they
are spliced into the wires leading to the controller. Cut out the
old splice and throw it away. Attach the valve wires to the open end
terminals of the battery chain. Does the valve fully open as it did
when manually operated? If so the valve is OK. If not the valve is
bad, replace it.
Next test the voltage output from the controller for each valve
stations. It should be at least 24 volts and over 0.5 amp. If you
don’t have the equipment to load test the controller for amperage you
can remove the controller from the wall and take it out near the
valves. Then run new wires from the controller to the valve wires.
Get a long extension cord so you can plug the controller in and then
turn on the valve manually using the controller. If the controller
is working correctly the valve should fully open. If the controller
checks out, then the wires between the controller and the valves are
bad and need to be replaced. If not, then the controller is bad and
needs to be replaced.
If the valves, controller and wires are ok, the problem is a
restriction in the piping. It could just be that the pipe is too
small, causing excessive friction loss. It could be sand or muck
buildup in the pipe. It could be a piece of metal, a rock, a rag, or
whatever stuck in one of the pipes. I’ve seen everything from fish to
toys in pipes.
Remove the last sprinkler heads and the sprinkler head riser on each
valve circuit. Cut the ell off the pipe where the last sprinkler was
connected to the lateral pipe. Install a new 45 degree ell on the
end of the pipe and a short length of pipe extending above ground.
The purpose of this is to get rid of the restrictions that a 90
degree ell and the riser create so you can get a good high velocity
flow to flush out the pipes. The outlet pipe needs to be above
ground to prevent dirty water from being sucked back into the pipes
after flushing. Turn the water on and allow the water to flush for
at least 5 minutes. After everything dries out, cut the flush outlet
off and reinstall the sprinkler. Test to see if that cured the
If not, there is probably something wedged tightly in the pipes
somewhere, so the next step is to isolate where that restriction is.
Prepare to get a wet while doing this test! You will need a 0-100
PSI pressure gauge. If you have rotor-type sprinklers get a “pitot
tube” to attach to the gauge. You can get one at an irrigation
store, call first, not everyone will have one in stock. The pitot
tube goes into the sprinkler nozzle so that you can measure the
pressure while the sprinkler is operating (doesn’t work for spray
heads, only rotors). If you have newer spray type heads with
industry standard female thread nozzles you can get an attachment
that allows you to install a pressure gauge on the sprinkler in place
of the nozzle. The attachment you need is a Rainbird #PA-80 adapter.
If you have male thread nozzles (Toro) or a non-standard nozzle
spray heads you will need to remove the the sprinkler head and attach
the pressure gauge directly to the sprinkler riser pipe where the
head was attached. This will require a few fittings and a short
length of threaded pipe.
Measure the sprinkler pressure at each sprinkler head location
starting with the last head and moving back toward the valve. Write
down the pressure for each sprinkler. If there is a large drop
between any two heads then that is where the problem is, drop down a
few paragraphs for instructions on how to fix the problem. If not,
then the problem is either someplace before the first sprinkler.
Tap into the mainline pipe just before the valve and install a tee on
the mainline and your pressure gauge. Turn on the valve and take a
pressure reading with one sprinkler circuit running. The pressure
should be around 5-10 PSI higher than the pressure you measured at
the first sprinkler after the valve. If it is more than that there
is probably something stuck in the pipe between the valve and the
first sprinkler. However, note that the pressure drop through
different brands of valves varies, so it might just be a high
pressure loss valve.
Next check the mainline for excess pressure loss. Tap into the
mainline right after the point where it connects to your water supply
and install your pressure gauge. Again, take a pressure measurement
while one of the valves is operating (it needs to be the same valve
as with the previous measurement). The pressure difference between
this point and the pressure reading you took at the valves should
generally be not more than 5 PSI. Again this varies dependant upon
the length of the mainline. If you have over 100 feet of mainline
the loss may be higher.
If you still don’t find an unusual pressure drop the problem is
probably just a poorly designed sprinkler system. The pipes are
likely all too small. There are no good solutions at this point
other than to trash the sprinkler system and start over. You can try
to divide up the larger valve zones into two new valves to reduce the
flow and thus the pressure loss. To determine if this will work,
remove and cap off half the sprinklers and test it. If it works
good, you can install a new valve and pipe to the capped off
sprinklers. But such approaches are usually less than satisfactory.
Consider seriously if it would be less work to just install a new
system that will work efficiently and correctly. My experience is
that you wind up paying more over the long run if you try to hack
together a cheap fix for a bad system.
If you think you may have an obstruction in the pipe:
Once you find the general location of the obstruction in the pipe
using the procedures above, the only solution is to start digging out
the pipe. Start by cutting out the fittings under the sprinklers,
most often if something is stuck in the pipe it will be wedged into a
If you cut out a pipe and need to replace it I suggest using the next
pipe size larger than the old pipe for the new one. It will not hurt
the sprinkler performance to use a larger pipe and it may help it.
It is worth the cost of the larger pipe. Where the new pipe connects
into the old ones use a reducer fitting to change sizes.
If you have an underground sprinkler system (drip systems too), somewhere out in your yard there are buried pipes, wires, and maybe even valves. But where are they? Sometimes they are above ground, so all you need to do is look around a bit. If not, then they aren’t visible because they are buried. (Big sigh.) You have perhaps the toughest problem there is in the irrigation repair business. There are no easy and inexpensive ways to find a valve, pipe, or wire. While this article addresses primarily valves, the methods for finding pipes or wires are basically the same.
Before we get going on how to find a valve let me make a couple of comments about what to do when you do find it.
Digging it Up
Once you find the valve you will probably need to dig it up. If you’re lucky it will be in a valve box and the box will not have been filled with dirt by some gopher. If there is a box be prepared to find critters inside the box when you open it! Use a shovel to pry the lid off from a safer distance. If the valve is not in a box, you need to be really careful when digging. Electric solenoid valves have wires attached to them that are very easy to cut with a shovel and very hard to repair once cut. Also if you hit the solenoid with a shovel you will probably break it and possibly break the valve as well. Even the valve body is easily cut as well as the pipe. So go slow and easy. Dig around the valve using a hand trowel. Better yet (I know this makes a mess!) you can use the stream from a garden hose with a patio cleaning nozzle on it to dig and use the water blast to loosen the dirt around the valve and wires. A plastic drink cup (ie; a McDonald’s cup) works good scoop out the muddy water and is unlikely to damage the valve.
If you cut or even nick the insulation on a wire, splice it back together using a water-proof splice kit made for underground wire splices. It is really important that the bare metal not be exposed to soil or water. Electrical tape alone will NOT work as a splice water-proofer! If the metal wire itself is not damaged you can seal the damaged insulation on the wire by coating the damaged area with several thick layers of PVC cement (glue). Let it dry then wrap the entire area tightly with plastic electrical tape, extending several inches beyond the damaged insulation. Then coat the tape with pvc cement. This is not the best solution, but it usually works.
If the metal wire is damaged (even if it is just partially cut) you need to cut out the damaged section and splice in a new section of wire. Use special water-proof splice connectors you can buy at any hardware store for ALL your irrigation wire splices and connections. Even ones above ground! If any water leaks into the splice it will corrode the wire. Even if the wire is not corroded through, the corrosion can block enough electric current to make the valve not open. If the wire breaks or corrodes it will be a major pain to find where the problem area in the wire is. You will probably have to replace all of the wire. You do not want to have to do that! Water-proof those splices. Got it?
I strongly recommend that if you splice or repair a underground wire you put a valve box over the repair rather than just burying it. Any splice or wire repair is going to be a likely source of future problems. The box will help protect it and will allow you to more easily locate the splice/repair in the future if you should have problems. If you can’t put a box over it put something else there that will help you locate it, like a metal tent stake driven fully into the ground at the splice location. You can find the stake with a metal detector. Make a note diagramming the location of the splice/repair and put it in the irrigation controller case.
Be Prepared to Replace the Valve
There is a pretty good chance that if you can’t find the valve you will need to replace or repair it when you do. That’s just how the odds stack up. If the system is in such bad shape that you can’t find the valves, usually the valves are in bad shape also. So prepare yourself now for that expense and effort.
Once you find your valve, put a valve box around it! Irrigation valves are often marketed as “direct-burial”, but as you now know (or will soon discover), finding one that has been buried directly in the dirt is very difficult. It doesn’t need to be a big fancy box, they make nice little inexpensive ones that work fine. Even a used plastic bucket or gallon size paint can flipped upside down will make a decent temporary valve box until you can afford something better. It just isn’t a good idea to bury a solenoid valve directly in dirt. Besides the problem of finding it later, burying it can also make it fail faster. Plus you are a lot more likely to damage a valve buried in dirt when you dig it up for repairs. And all valves are going to need to be repaired someday! So put those underground valves in boxes, and while you’re at it, put 4″ of gravel under the box! The gravel keeps gophers from digging into the box from underneath and filling the box with dirt. You can buy a small bag of gravel at most home improvement stores. (Decorative rock works also, especially that rough surface lava rock.) You might also want to measure and write down where the box is located as measured from a couple of fixed locations, such as a house wall or fence. That helps you find it if grass grows over the top of it… if you don’t lose the measurements!
OK, time to get to work.
How to Find a Buried Valve
1. Start by trying to figure out what the most likely place is where the valve would be installed. To do this you need to try to “get inside the head” of whomever originally installed the system. This helps cut down the “search area”. Do you know where other valves are in the yard? Are they each inside the area they water? If so, the others are probably inside the area they water also. Are they grouped together? Then the others may be nearby. Maybe there is a pattern to the placement of the valves, all on one side of the yard perhaps, or all in a row? If you don’t know where any of the valves are, you still know a pipe takes water to them. Find where that pipe connects to your water supply. Now try to figure out which way the pipe goes from there. Sometimes if you look real close you can see a slight indentation in the soil where the trench for the pipe was dug. Another tip, the grass is often just slightly greener where the trench was dug. For lawns, if you mow the grass short and look across the surface you can often see slight “troughs” where the trenches were dug and the soil has settled.
If you have the original plans for the sprinkler system they may help you find the valves, pipes and wire locations. If this is a commercial irrigation system the local building inspector or planning department may have a copy of the plans. However, even if you do have the plans, chances are the valves aren’t located where the plans show them. So I wouldn’t waste too much time looking for plans. In 35 years of practice and thousands of irrigation systems, I seldom saw the contractors install the valves exactly where they were shown on my plans. Even when I required my contractors to label and dimension the valve locations, I often discovered they just made up the dimensions!! At best a plan might give you a hint as to where to look.
2. If the valve you are looking for is an electric valve that actually still works, try turning the valve on and see if you can hear the solenoid buzzing or water whizzing through the valve. Try using a mechanic’s stethoscope placed on the ground to listen. Or cut the bottom out of a paper cup, place it upside down on the ground, and put your ear over the top. Do this late at night or in early morning to reduce background noise and make it easier to hear. Note; if the neighbors see you they will think you’ve lost your mind!
3. Try a metal detector if you own or can borrow one. I’ve honestly never tried this, but some people tell me it works, and it seems logical. Most valves have at least a little metal in them, although the cheapest ones have very little. The solenoid on an automatic valve has a bit of metal in it also. If you have, or can borrow, a metal detector you may be able to locate the valve or the wires with it. If the valve or wire are buried deep, a low cost metal detector will probably not find them. In my opinion the chances of success using a metal detector probably are not good enough to make it worth the expense of buying one. But if you have one or can borrow one, why not try it? I’d love to get your feedback on use of a metal detector if you try it!
Try following the pipe to the valve using a metal detector. According to reader James P. you can trace the location of a pipe using a metal detector and a “fishing tape” (aka; draw wire or draw tape). A fishing tape is a long tape used by electricians, they inserted the tape into conduits to pull wires through them. The tape needs to be metal or at least it needs to have a metal section at the end of the tape that you can detect. You need to cut the pipe open, then you insert the tape into the pipe. A high-quality metal detector (he warns the cheap ones aren’t powerful enough) can then be used to trace the location of the end of the tape from the ground surface. You may have to follow the route in sections depending on the length of the tape. Also if there are any tees or ells in the pipe the tape will not easily slide past them, so you may need to dig a few potholes to cut into each new section of pipe after a tee or ell. Repair the sections of pipe you cut out to insert the tape using repair couplings or compression couplings. You will find these at any hardware or home improvement store.
4. Use a valve chatterer. This won’t work if the wires to the valve are cut or broken. So if you’re trying to find an automatic valve that won’t open, a chatterer is not likely going to help. A chatterer is a electrical device you put on the valve wire that makes the valve rapidly turn on and off. The result is that some brands of solenoid make a loud clicking or chattering sound that will give away it’s location. Unfortunately some valve brands don’t make much noise at all. And the deeper the valve is buried, the harder it will be to hear it chatter. Most irrigation pro’s have valve testers that include a chatter function along with other testing tools. These are handy tool for diagnosing valve electrical problems, but tend to be priced beyond what is justifiable for a homeowner to buy. (See ads for typical chattering devices at right. Also see my review of the Armada Pro48, which is the one I use.) To use a chatterer you disconnect the valve’s wires from the controller/timer and hook them up to the chatterer device. Turn the chatterer on and the valve should rapidly open and close and create a noise. Just like with listening for the water running through the pipe, you will have to go out in the yard and listen for the chattering, and it will help if it is during a quiet time of the day.
Make your own chatterer. All you will need is three 9-volt batteries and a friend with dexterous fingers. Someone who texts a lot on their phone is perfect! Start by making a valve actuator. Here’s how to make one out of three 9-volt batteries. To chatter the valve simply attach one of the valve wires to one terminal of your home-made actuator and tap the other wire against the other terminal of the actuator. Tap the wire at one second intervals. It doesn’t matter which wire goes to which terminal. The valve should turn on and off with each tap and make a clicking sound. I don’t recommend tapping the wires on the controller/timer terminals to chatter the valves. If you slip up while trying to tap the wires against the terminals and short circuit the wires you can damage the controller/timer. Destroying an expensive controller will ruin your day!
5. Water Dowsing, aka; water witching. This is a method of finding a water filled pipe by walking slowly while holding a branched stick or a couple of bent wires in your hands. I won’t try to explain how to do it, you can look it up if you want to try it. I’ve never witnessed it done successfully firsthand. But I have met several people over the years who have either seen it done successfully or done it themselves successfully. This includes people I trust, so I’m not in doubt of their claims. Did they see or do what they thought they did? The answer to that thorny question I will leave to you to decide!
OK, the science behind dowsing is very shaky- at best. Most explanations I have heard are that those with the talent are able to read subtle signs on the ground surface that indicate the location of water or the pipe. They then subconsciously transfer that information to the movements of the sticks, like a Ouija Game. Maybe. But most of those I’ve talked to say that the force on the stick/wire is very strong and not likely to be from anything subconscious.
Everyone I know who claims dowsing works or that they have the ability to do it IS an expert who has worked in the industry many years. I can tell you that with 35 years of experience I can often look at an irrigated area and tell you where the pipes are with reasonable accuracy. No sticks needed. Just lots of experience looking at irrigation systems, and hints like those I’ve already covered, dips in the ground surface where trenches have settled, areas that are greener than others, etc. At any rate, I don’t want to get into any arguments over dowsing. I present it as an option that many believe works. If you can find someone with the talent, they may, or may not, be able to help you find the pipes, valves, or wires (yes, some dowsers claim they can find wires too!)
6. Use a wire locator (aka; wire tracer) device. This is how the pros do it, but if you notice the cost of a wire locator (ads on right), you will probably find that if you are a homeowner it is not within your budget! Some tool rental places, especially those that cater to professional contractors, have wire tracers they rent. (Sprinkler Warehouse rents wire tracers using overnight shipment.) You use a wire tracer to follow the path of the wires to the valve, starting at the controller/timer. Again, if the wire is broken you may not be able to follow it (although the better units can even jump the signal over small wire breaks. However, it will find the location of the break so you can repair the break in the wire. Then you can continue tracing the wire to the valve– or the next break in the wire! ) Also be aware that it takes a bit of practice to use a wire tracer, but it can be mastered in a few hours. The way it works is that you attach a signal generator attached to the valve wire. Then you use a receiver that senses the signal. The receiver beeps when you are near the wire. A word of warning on wire tracers. You need a tracer with a signal generator that is powerful enough for the sensor to be able to pick up the signal through 24″of dirt depth. While most residential irrigation wires are not installed that deep, they are supposed to be! The wire tracers made for use by electricians to find wires in house walls are not powerful enough to detect buried wires, even if they are only a few inches deep. I have one made for detecting wires in walls, that also lists irrigation systems as a suitable use, and it will NOT detect wires buried even 1″ below ground!!! So before you spend money, make sure the device is suitable for wires that are buried underground.
Hey, do you know someone who works as a line-person for a phone or cable company? They may have access to a wire locator since they often use them for repairs. Maybe this weekend they might trade a few minutes of their time for a couple of beers? hmmmm?
Now for the “this is a lot of work” solutions! Start with a trip to the store to stock up on Advil and Ben-Gay.
7. Probing for valve boxes. Before you try digging, first try a shallow probe for valve boxes. If valve boxes were placed over the valves when the system was installed, they are probably just below the surface. Often the only reason you can’t see them is that grass grew over the top of them. A pitch fork is ideal for probing for the boxes, just gently stab the ground until you hear the clunk of a fork tine hitting the plastic box top. If you don’t have a pitch fork a metal yard rake works for some people (others can’t get the motion right to plant the rake tines through the grass), a stick with a long nail-spike on the end of it works good to probe the ground, and last resort is to use a screwdriver on your hands and knees (ouch!) Again, use logic to figure out the best place to start probing.
8. Probe or dig to find the pipes. (My back is hurting just from writing about it.) If no valve boxes were used, then you will need to probe deeper. Now, just to warn you, it is highly likely you will cut or break a pipe or wire while you are doing this. So just be prepared for that as a cost of the process of finding the valve. OK. Fortunately installers who don’t use valve boxes also tend to not bury the pipe and valves very deep, cause they’re lazy and cheap. Normally the pipe from the water supply to the valve is buried deeper than the pipe from the valve to the sprinkler heads. (This pipe is called the “mainline” and is supposed to be at least 18 inches deep!) Plus the wires normally are thrown in the same trench with that mainline pipe going to the valves, and you don’t want to cut or nick a wire with a screwdriver blade. So it’s best to start at a sprinkler head and work backwards toward the valve. Use a long blade screwdriver to gently probe for the pipe around the sprinkler. Try to pick a sprinkler head you think might be close to the valve. If you can turn on the sprinklers, the one closest to the valve will often come on slightly quicker than the others, and have more pressure, so it will have a more “powerful” sound and forceful spray when it is operating. Be gentle when probing, don’t break or pierce the pipe! Once you find the pipe keep probing and follow it back to the valve. If the ground is really dry and hard, you might want to water it to soften it up first. As you follow the pipe consider marking the pipe locations on the grass or dirt using some of that special marking spray paint or the little sprinler flags they sell at irrigation supply stores. Marking the pipe location will help you track where you found pipes (ie; this could be a multi-day project!) Tip; draw yourself a diagram of the sprinkler pipe locations for future use as you find out where the pipes are!
What if you can’t find the pipes with a screwdriver? Well, in that case it’s time for a shovel. Have fun digging up the yard! 🙁
Small mainline leaks can be a really tough problem to deal with. A master valve will cure the symptoms for a while. The master valve should be the same size as the other valves unless you run more than one valve at a time. It is installed at the connection point of the irrigation system to the water supply. You will need a irrigation controller that has a master valve circuit on it (sometimes called a “pump start circuit”, the two are the same thing.) You wire the master valve to the master valve circuit on the controller using two wires, just like any other valve. It will then open whenever any other valve on the system opens to irrigate. When the irrigation is complete, the master valve will close which will relieve the pressure on the mainline, stopping the leak.
However this does not cure the leak, which will continue to get worse as the water erodes the pipe around the leak and the hole gets larger. Also, master vales come with their own unique problems. With a master valve the leak may (depending on it’s size and location) drain the water out of the mainline after each irrigation, which will cause new problems. The system will spit air each time it starts up and make lots of noise. This also weakens the pipe over time due to the stress of refilling with water at the start of each irrigation. The sprinklers will also not run efficiently for the first minute or so as the air is expelled. Next, dirt may be sucked into the mainline through the leak hole when the system depressurizes. The dirt can then get into the valves and sprinklers causing them to fail. Finally, pressurizing and depressurizing the mainline causes it to wear out earlier than normal. (Think of inflating a balloon and releasing the air over and over. It wears out the plastic and then the balloon pops. Same with your mainline.) How much impact this has is a matter of debate in the irrigation industry, the difference might be that your mainline only lasts 15 years rather than 20. Again, it varies depending on your system, the higher your water pressure the more likely damage will occur.
Finding a leak can be very difficult, there is no easy way that I know of. The only way I know of to find a leak is to visually inspect for it. This is hard with buried pipe. First inspect for leaks around the obvious places like the threaded connections to the valves. Threaded joints are by far the most common locations for leaks. Clean and thoroughly dry any water off of the connections with a towel, wait a few minutes, then wipe the connection with a paper towel and see if the paper gets wet, indicating a small leak.
You may be able to hear the leak if it is fairly large, but a slow drip will not make enough noise. You can make a “stethoscope” to listen with using a cardboard tube like the ones used as used for wrapping paper.
Also you can look for mud or soft wet dirt around the leak. Try probing the ground with a long screwdriver, looking for soil that is wetter than other areas. Then start digging. You may have to just wait until it gets bad enough to become visible.
The easiest “do-it-yourself” way to get a pipe under pavement is
hydraulic boring. Take the pipe you want to place under the driveway
and connect a sweeper nozzle (used to hose off driveways) to one end
and a hose to the other. Glue “hose thread” adapters to the ends of
the pipe to connect the nozzle and hose (you’ll need one male and one
female adapter). Dig a trench on one side of the driveway and an
exit hole aligned with the trench on the other. Turn on the water
and shove the pipe under the driveway. The water blast from the
nozzle will dig a hole as you push the pipe under. Be prepared to
get very dirty and wet! After the pipe is under the driveway, remove
the nozzle and hose, and cut off the adapters. You now have a pipe
under the driveway. The hole around the pipe will be somewhat larger
than the pipe, which can cause a problem with asphalt driveways. If
the soil above the hole collapses, the asphalt will give way under
the weight of a car. If you want to chance it with an asphalt
driveway, make sure the pipe is 18″ deep under the asphalt, so there
is more soil to support the weight. You can dry to push concrete
into the hole around the pipe to fill it in and give more support,
but this is difficult to do.
Boring tools are available which work better in rocky soils and under
asphalt. These tools “drill” a hole using a bit. You can rent them
at some rental yards, but in most cases you are better off hiring
someone to do it for you. These guys have boring tools that can
drill over 100′ and even can make minor turns as they bore. So they
can get a pipe from the front yard to the back under a sidewalk or
patio. When boring under asphalt, most boring companies will install
a sleeve as part of the boring work to support the surrounding soil
and prevent the asphalt from settling. You then push your irrigation
pipe through the sleeve. Look in the yellow pages under “Plumbing”
for companies that do “trenchless” installation or “boring”. If none
list those services in their ads, try calling a professional plumbing
supply store and ask if they can give you a referral to a company
that does boring. Often these specialized companies are just one guy
with a boring machine and don’t advertise. They tend to be pretty
busy because of all the communications cable installation going on
with the Internet expansion. Most telephone cables are now bored
into place to minimize damage to roads and property.
Sometimes for asphalt driveways you will need to “sawcut” a trench
through the driveway, then repair the driveway after the pipe is
installed. For companies that saw asphalt look in the yellow pages
under “Concrete Breaking, Cutting & Sawing”.
Most pros poison them, but we have lots of pets in our area so I don’t like to use poisons. I trap them with a gopher trap (the kind with spring loaded spikes that drive into their head to kill them, it’s gruesome but very effective.) Place a rope on the trap and tie the other end to a stake. Dig a 12″ diameter hole to expose a tunnel, then slide the trap into the tunnel. Place some fresh grass clippings in the hole behind the trap as bait. Cover the hole with a piece of plywood and place dirt around the plywood to seal out all light. The next morning remove the plywood and pull on the rope to remove the (hopefully dead) gopher.
Q. I just restarted my sprinkler system after it had been winterized. When I turned on the water to the system, all the valves stations came on at once, as if by-passing the timer unit. Even when I turn the timer unit Off, the sprinklers keep running.
A. This is a common problem when restarting after your sprinkler system has been winterized, or after the system has been turned off for an extended period of time. It also often occurs with brand new solenoid valves that have just been installed. There are a couple of possible problems that can cause this, so we’ll look at a couple of solutions. One of the tricks below should get your irrigation valves opening and closing properly again.
Air Trapped in the Valve:
The valves may have air trapped in them. A small bubble of air becomes trapped in the tiny water ports of the valve, this stops the water from flowing through the port. Since the water flowing through the port is what holds the valve diaphragm closed, the valve stays open.
1. Turn on the main water supply.
2. Now go to the individual valves and using the manual open & close control on the valve. The manual open & close control is either a lever on the valve (most often it is under the valve’s solenoid), or it may be a screw on the top of the valve bonnet. If it is a screw don’t fully remove it, just open it until water starts squirting out. Set it to open, wait a few seconds, then set back to closed. If the valve doesn’t close within a minute, try it again. It may take several tries to get the air bubble to “burp” itself out. Try tapping the valve to dislodge the air while the valve is open if needed. Note: old plastic valves may become brittle and crack when tapped, so if the valve is plastic and old don’t tap on it except as a last resort if the air doesn’t come out.
3. If that doesn’t fix the problem, you can almost always force the air out using the manual flow control on the valves. Unfortunately, some inexpensive valves do not have a flow control. The flow control is a handle, similar to what a manual valve has, that is on the top of the valve. It works just like a regular faucet, turn clockwise to close. Most flow controls have a hand operated flow control, others have a cross handle that is turned using a tool (pliers will work if you don’t have the special valve opening tool.) A few valves have a screw for the flow control that requires a screwdriver to turn. Try completely closing and then reopening the manual flow control on each valve. That should force the air out and fix the problem.
Valve Needs to be Throttled:
If air in the valve doesn’t seem to be the problem it is possible that your valves don’t have enough pressure differential and they need to be throttled in order for them to close by themselves.
Here’s how to throttle them using the flow control adjustment:
Note: some inexpensive valves do not have a flow control adjustment feature on them. If that is the case you are not going to be able to do this. You will need to replace the valve with a better quality valve that has a flow control.
1. Use the manual flow control on each valve to close all of the valves. Now the main water supply should be on, but none of the valves should be allowing water through. So no sprinklers are running.
2. Start with just one valve at a time. Rotate the manual on/off lever to the on position. Open the manual flow control knob all the way (turn as far as it will go counterclockwise). The valve should come on and sprinklers run.
3. Next rotate the manual on/off lever under the solenoid to the closed position. The valve should close (it may take it a minute or two to close) but probably won’t, because that is the problem, they won’t close! If the sprinklers turn off the valve is working correctly, go to the next valve and start again with step #2. If the valve does not close by itself, you need to throttle the valve. Continue to step #4.
4. To throttle the valve you partially close the flow control knob. Start by turning it one full turn clockwise. Wait a minute for the valve to close. If it doesn’t close, turn the handle another half turn clockwise. Wait again. If the valve still doesn’t close turn it another half turn. Keep doing this, at some point the valve should suddenly make a whooshing noise and close. If the valve is broken it will never close by itself and eventually as you close the flow control more and more the sprinkler radius will start becoming noticeably reduced. If that happens you need to repair or replace the valve. But in most cases the valve will close by itself after you have partially closed the flow control. It might take 4-5 complete turns before this happens.
You shouldn’t see any significant change in the sprinkler performance with the valve flow control in the partially closed position, except that the sprinklers may mist a little less (which is a good thing.) This is called “throttling the valve” and some valves won’t close by themselves unless they are throttled. The way a solenoid valve works is that the pressure differential as the water goes through the valve is what the valve uses to power itself into the closed position. If there isn’t enough pressure differential the valve will not close by itself. Often there is not enough pressure differential when there aren’t very many sprinklers on the valve circuit. When you throttle the flow control you are simply increasing the pressure diferential.
You can leave the flow control in a partially closed position permanently, it will not hurt the valve. The valve is designed to allow you to do this. The sprinklers should still operate well as the amount of water throttled when you partially close the valve is not significant.
Q. I have manual shut-off valves installed downstream from my electronic anti-siphon valves. I installed them to turn off the water to parts of my yard where I grow annuals and only need to water for a few months out of the year. I would really appreciate it if you would explain why valves downstream cause the anti-siphon valve backflow prevention to fail.
A. If there are some sprinklers that are not shut off by the downstream valves (ie; there is always a sprinkler that will be on when the anti-siphon valve is on) then you should be fine. The key to this is that when the anti-siphon valve is closed the water remaining in the pipe downstream of the anti-siphon valve MUST become depressurized. Depressurizing normally occurs when you shut off the anti-siphon valve and the remaining water pressure in the downstream pipes is released through a sprinkler. But if you have a valve downstream of the anti-siphon valve it will trap pressurized water in the pipe between the anti-siphon valve and the downstream valve and not allow it to “depressurize”. Note that sprinkler heads with built-in check valves will also hold the water pressure in the pipe. That is why when using anti-siphon valves you should remove the check valve from at least one of the sprinklers on each valve circuit (normally you would remove it from the sprinkler on the circuit with the highest elevation.) the check valves are easy to remove from the sprinklers, normally you just unscrew the sprinkler cap and lift out the riser assembly. You will see a rubber washer attached to the bottom of the riser assembly, pull it off. That rubber washer is the check valve seal, with it removed the check valve won’t work. Now reassemble the sprinkler.
How an anti-siphon valve works:
The anti-siphon valve works by use of a little air vent that is located on the downstream side of the actual valve. Look at the anti-siphon valve you will see there is a large cap directly above the water outlet of the valve, the air vent is under this cap. If you look closely at the lower perimeter of the cap you will see holes or slits that allow the air to move in and out of the vent. When the anti-siphon valve is turned off the pressure drops in the pipes downstream from it as the remaining water flows out of the sprinklers. When the pressure drops the little air vent drops open and lets air into the pipe right behind the valve. This air goes into the pipe and breaks any siphon effect (“anti-siphon”) so that sprinkler water can’t be drawn backward through the valve into the potable water supply.
(Water from the sprinkler pipes can be siphoned back into the water supply system when pressure is lost in the water supply system. For example, the water company might depressurize their pipes to make repairs. It doesn’t happen frequently, but it does happen. When the pressure drops the flow reverses and water from the sprinkler pipes, along with dirt and other yucky stuff, can be sucked in through the sprinklers and then into the water supply system. When the pressure returns that dirty sprinkler water may go back into the sprinkler system, but it may just as easily go to your kitchen or bathroom sink. So why wouldn’t the closed anti-siphon valve stop this from happening? After all the purpose of a valve is to stop water from flowing through it when it is closed, right? Yes, of course, if the valve is a manual valve. But electric solenoid valves are “directional” valves. What that means is they are designed to stop the flow when the water is flowing in one direction only. When the water flows backwards they don’t fully close!)
What the downstream valve does:
If you have another shut-off valve after the anti-siphon valve, then the water on the downstream side of the anti-siphon valve will stay pressurized even when the anti-siphon valve is closed. This water pressure holds the little air vent in the closed position so it can’t let in air, and therefore the siphon effect is not broken. This means the anti-siphon part of the valve will not work. Even worse, when the little vent is held closed for days at a time due to the constant downstream pressure, it eventually just sticks in the closed position. Then even if the pressure drops the anti-siphon won’t work.
My Friend or Irrigation Person Says This is All Just Something YOU Made Up!
Unfortunately, this wrong practice of installing valves after an anti-siphon valve is pretty common in the irrigation industry. I’ve been called some pretty ugly names over this issue. Fortunately for me, you don’t have to take my word for it. Tell your friend/buddy/pal to read the box the anti-siphon valve came in. It says right on it “do not install valves downstream” or something similar. If you don’t have the box or it didn’t come in one, then go to the manufacturer’s website and find the anti-siphon valve installation instructions. You will find that same warning. Here’s a sample from Rainbird if you want to check for yourself: Rainbird Anti-siphon Valve Operation Manual. See the section that starts with the heading “CAUTION”.
Q. Is it possible to have two valves on at the same time or to run two irrigation valves at once?
A. Yes, it is often possible to run two valves at once. However there are several problems that can occur.
You must have a sufficient water supply for both valves to run at once. If the performance of the sprinklers suffers and you start seeing dry spots in the landscape, you obviously don’t have enough water. You may need to do some adjusting of the sprinklers as the water pressure operating them is likely to be less when two valves are on.
Both valves running at the same time may require more water than the pipe supplying them can reasonably handle. This can result in water hammer, or premature pipe wear/failure, due to high water velocity.
Water Hammer: Listen for a loud water hammer “thump” or “bang” noise when the valves close. A gentle thump is fine, but if the pipes reverberate from it that is not good. Run just one valve and listen to the sound when it closes. Assuming the irrigation is properly designed, that should be the “normal” closing sound. Now listen to the sound when both valves are closed together to see if it is significantly louder. If it is significantly louder, that is not good. You can possibly reduce or eliminate the water hammer problem by closing the valves separately, one at a time.
High Velocity: Premature wear due to velocity is harder to figure out. It generally isn’t a problem unless the water is really flowing fast through the pipe, like 8 feet per second or higher. The only way to determine if it is a problem is to do a couple of calculations. Start with the sprinklers. On top of each sprinkler is an identifying names and part numbers that tell you the brand, model, and hopefully the nozzle size. Write down that information for each sprinkler, then look up the water use (GPM value) for that sprinkler and nozzle at the sprinkler company’s website. (You may need to call the company’s help line to assist you, each brand and model is different so I can’t give exact instructions.) Now add together the GPM values for all the sprinklers that are running at the same time when two valves are turned on. This will tell you how much water the two valves require when running together. Next find the size and type of the water pipe that leads to the valves. (For example it might be a 3/4″ copper tube, or maybe a 1″ PVC pipe. It may be several different sizes and types of pipe, in which case you would use the smallest pipe size and type.) Using that information you can calculate the velocity of the flow in the pipe using the Friction Loss Calculator at https://www.irrigationtutorials.com/formulas.htm#sec8. Just enter the pipe type, size, and GPM into the calculator and it will give you the velocity.
If you decide to use a controller to operate the valves the controller must be a brand that provides sufficient amperage to run two valves at the same time (most do.) If you want the controller to run the valves at the same time, but start and stop them about one minute apart to reduce water hammer, you will need a controller that allows you to run two separate valve zones at the same time. Most controllers have a “stacking feature” that prevents them from doing this. You will need a controller that allows you to turn off the stacking feature. Most controllers can’t do this. You will probably need to enlist a knowledgeable controller salesman at a professional irrigation supply store to assist you in finding a controller that will work for this unique situation.
Q. I’m installing a drip irrigation system and to save some money, I decided to buy inch wide black tubing. I used a hot needle to make some small holes every 27 inches apart from each other, but when doing water pressure testing , some holes emit more water than others. What do you recommend in this case? Is it a bad idea to punch my own holes? Or is there a way to do this with an even result in each hole?
A. Just punching holes doesn’t work well, as you discovered. It’s almost impossible to get the holes uniform in size, and even if you did, variations in the water flow patterns inside the tube would make each hole emit water at a different rate. The solution is simple. You need to install barbed drip emitters in the holes. The drip emitters are small, plastic, highly-engineered devices that regulate how much water comes out, so that each hole gives a very uniform rate of flow. A typical emitter (sometimes called a dripper) is about the size of 5 dimes stacked on top of each other. The emitter has a barbed inlet on one side that pushes into the holes in the tube. You just snap the barb into a hole punched in the tube. Then the water drips evenly out of an outlet hole on the other side of the emitter. You need one emitter for each hole. Emitters are typically sold in packages of 10, 25, 50, or 100 emitters per package.
Since you already bought tube, cut off a small piece of your tubing that has a hole in it and take it with you to the store. 1″ black tube is probably not made for use with drip systems. It probably has a thicker wall than standard drip system tubing, so the barbs on some brands of emitters may not be long enough to push all the way into the tube and lock in place. Most brands should work, but in your case it would be best to test it at the store so you don’t have to make another trip back to the store if the emitters don’t fit. The emitter’s barb should push all the way in and lock the emitter onto the tube. It should not easily pull out.
Q: The pressure is blowing off the pipes/tubes from the barbed fittings on my drip irrigation system. This is only happening on hot days (30°C=86°F in the shade). Pipe temperature could be as high as 45°C=113°F. Our water pressure varies between 2.5 and 3.1 bar (35 and 45 PSI.)
A: Drip tube should not blow off the barbs, even on a hot day when the temperature softens the plastic tubing (however the heat does make it easier for them to blow off!) There are three common reasons the tubes blow off.
1. The most common problem is that the water pressure is too high. This is probably your problem. The water pressure should be around 1.3 to 2.0 bars (20 – 30 PSI). You should install a pressure reducer after your valve to lower the pressure.
2. The pipe and fittings may not be the same size. This is one of the pitfalls I warn about in my Drip Guidelines. 16mm and 18mm tube are both commonly referred to as 1/2 inch in the USA! The fittings for these two are not interchangeable.
3. Pressure spikes can pass through the less expensive pressure reducers often sold for drip systems. If you have high water pressure this may be the problem. The solution is to install a high quality brass pressure reducer valves. These generally are sold in the plumbing department rather than the irrigation department of stores and cost $50.00 or more.
Common sizes are 12 mm (0.455″ or 3/8″), 16mm (0.620″ or 1/2″), 18mm (0.720″ or 1/2″), and 24mm (0.940″ or 3/4″). Do you see the problem? Two sizes are commonly referred to as “1/2 inch” in the USA! The fittings for these two are not interchangeable.
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