Searching for Lawn Sprinkler Valves

April 10, 2009

sprinkler-valveFinding the lawn sprinkler valves can be challenging  without the correct tool. Most irrigators have a tool called a cable hound or cable locator. Think of this exercise as an Easter Egg Hunt and the valve is the candy.

Within all Lawn Sprinkler systems they are broken into zones. Each zone has its own electrically controlled valve. TIP: The valves are powered by 24V AC with a very low current flow and is not normally considered hazardous. This valve is activated by the sprinkler timer or controller. Depending on the installer and the application, some installers place them in a cluster where others place them throughout the yard, or a combination of both. In most cases, (not always) the installer will place the valves in an access can or valve boxes. Unfortunately over time,  these cans (or boxes) can easily disappear under the turf. So if you know where they are,  its good to keep the grass cut back from them or have them marked is some way.

Besides providing an isolation point, sprinkler valves can get dirty or become inoperable. For the most part, the valve can be serviced with replacement parts assuming you know the exact brand and model of the valve.  Read this link on sprinkler valve repair. If the valve is still leaking after a thorough cleaning and inspection, acquire a repair kit and replace all the parts. Rarely would you need to actually remove the valve body from the system unless it became frozen during the winter and the body was cracked. If it was cracked, you should have noticed the valve leaking before you started the dis-assembly process. TIP: Avoiding the cracked valve body is one of the reasons it is recommend to turn off and drain the sprinkler system in the off season.

Finding the valves can be challenging  without the correct tool. Most irrigators have a tool called a cable hound or cable locator. These test sets are about $400-500, so purchasing one is probably out of the question.100_0203 It may be possible to find a rental, but most people that require them usually own them.

Finding zone valves:

  • Cable locator: Professionals use a cable locator to find the valves by tracing the path of the electrical wires that feed each valve. If you have one of these tools or have access to one, this is the simplest and quickest method.  The tone typically get loud when you reach the valve. As an alternative to a Cable Hound, I have tried a low cost test set from Harbor Freight but cannot recommend it as it did not work as I had hoped. It was not really intended for this type of use, but it was worth a shot for the price.  As an alternative, you can hire an irrigator to make the repair and ask him to locate  all the other valves as well. They may not even charge you to find the other valves since they are charging you for the visit and repair.

So if you are going to try to locate them on your own without a locator, try the following methods:

  1. Design drawing. Hopefully you were left with a drawing from the installer or the previous owner of the property. If  you have any record of who 100_0409installed the system, they may still have one on file.   Find the valves identified on the drawing and use a long screw driver or probe and a shovel to poke around in the dirt. When you hit a valve box it will have a hollow sound to it. They will probably not be in the exact location but hopefully within about 5 feet from where the drawing indicates it.
  2. Origin of Water: The system should have a back flow preventer in a large rectangle box, usually near the water meter.  The sprinkler valve(s) will be located somewhere between the back flow preventer first sprinkler head. Look near the first head of each zone.
  3. Valve Chatter: Assuming you can still turn the system on and off, you can have a friend turn the system on/off multiple time. The valve will make a slapping or hammering noise that may be loud enough to pin point the valve location.
  4. If you have gone through this without sucess, you may have to call the Irrigator anyway, hopefully using some or all of these methods, you were able to find the valves.100_0411

Chasing Lawn Sprinkler Leaks

March 21, 2009
 Fixing easily corrected household water leaks can save homeowners more than 10 percent on their water bills. sprinkler21

       

 Unfortunately many of us require lawn sprinklers to have any kind of landscaping short of cactus, gravel and rocks. Having a lawn sprinkler system is kind of like garage door openers, once you have one its hard not to. Dragging hoses around the yard is a real pain and it becomes a challenge to keep things alive. Taking care of your sprinkler system will save you money,  reduce the opportunity to waste water and keep your plant material alive. With water restrictions  on the upswing,  more and more cities are assessing fines for violating the restrictions.  Check with your local municipality for restrictions regarding time of day, rain and freeze detection.  Adding a rain sensor to your system is a wise decision.   

Rain Sensor

Rain Sensor

   

Because sprinkler heads are not under pressure until the system is live,  it can be difficult to isolate the leaks. “Pop-ups”  are the most common spray heads found in  residential systems. Typically I find  pop-ups require more maintenance than the larger impulse or stream sprayers primarily due to the fact that pop-up sprayer use less water per head and the water orifices are smaller and they clog easily.  With pop-ups, it takes more heads per square foot to provide adequate coverage. The greater the distance between heads, the further the water has to spray.  To do this, the arc in the spray pattern has to be projected higher in the air.  As a result,  you lose up to 50% of the water in the air.  Up until the last year or so, we have seen little in the way of water miser type heads. These new type heads are designed to replace the pop-up with a miniature stream sprayer providing a coarse spray in lieu of a mist. This can help reduce water loss and your system may be retrofitted to use these type heads. However, it is important to match the right head for the system. When your system was designed,  it was all based on a certain water pressure, pipe size and GPM (gallon per minute) volume, so any changes need to take this into account otherwise you may end up over/under-watering. Not that a DIYer cant figure this out,  a good licenced irrigator can help you solve the problem. Also, take a look at this comparison study of nozzle types.   

Top 5 Reasons Why Water Sprinklers are Wasteful   

  • Poor design: System design that allows sprinklers to spray water across sidewalks or concrete cause water to be lost to evaporation and run off. 
  • Wrong watering times:  Running your water sprinklers in the middle of the day allows the water to evaporate before it has time to absorb in to the ground. 
  • Wrong water duration: Some believe short duration watering is a way to conserve water however, short shallow watering can cause turf and plants to experience stress because the shallow water can cause shallow roots.
  • Dirty nozzles: Even though sprinkler heads (should) have filters underneath the nozzles, they can still pass some particles in to the nozzle. Many times bad-sprinklerthese particles can be wedged in the spray nozzle causing it to mis-spray and not distribute water equally and efficiently throughout the spray pattern.
  • Lack of maintenance: Sprinkler heads take a lot of abuse from lawn mowers, string trimmers and edgers. Whether it be abuse,  leaky or bad sprinkler heads, all of these conditions can cause a lot of water to run down the sidewalk. 

Standard spray nozzles are approximately 50% efficient as the over-spray is lost in the air.  Loss and waste in a sprinkler system can be difficult to recognize without taking the time to exercise the system and inspect each sprinkler head while running.   

 Keeping your lawn sprinkler system in good working order is one of the easiest ways to get optimum performance from your system. Most all lawn sprinkler systems can be defined in two distinct parts:
  • Feeder or Pressure Lines: The side under pressure includes a cut off valve, double check valve (aka back flow prevention valve) and a valve for each zone and a lot of pipe. 
  • Distribution Lines or Zones: The system could include any number of  zones, this is all dependent on the size of the system. The zone has to be running to inspect it for leaks. Since the sprinklers are spraying water, finding leaks can be a bit more challenging.

Chasing Lawn Sprinkler Leaks   

Feeder or Pressure Line  Leaks:   

  1. Finding leaks in feeder/pressure lines is similar to the same process as found in the Chasing Water Leaks post. Turn off the main cut-off that will isolate the sprinkler system from the remaining water supply. If the flow meter stops proceed with the following steps.
  2. Locate each sprinkler valve in your system. If you are not sure how many valves are in your system, look at your Sprinkler Controller to identify how many sections or zones are in the system. Finding the sprinkler valve may be difficult as valves can be overgrown by grass or ground cover.  If you have the original installation drawing, it should identify the approximate locations of the valves. Before you hire a professional, try the methods described in Searching for Lawn Sprinkler Valves. Either way, once you find them, take note of their location for future use. 
  3. You may notice water residue around some sprinkler heads even when it should be dry, known as weeping, this could be a hint that the sprinkler valve is passing water when it should not be.
  4. Once the valves are located, they should be turned off, one at a time to determine if you have isolated the leak. Each valve has a manual cut off on the center top of the valve. Once you have isolated the leak to a specific zone, the problem will be resolved at the valve. (TIP: Sprinkler valve can be disassembled and cleaned without removing them from the system but the water must be shut off.) Most likely it just needs to be cleaned (that means taking it apart and removing any dirt or debris inside the housing),  but it could have been damaged during the winter months, if so, you may need to replace the valve. Read this tutorial for specific instructions on repairing a solenoid valve.

Distribution Lines or Zones: (Plan to get wet)   

  1. Run each section one at a time. Walk the zone looking for excess water accumulation around the head, the seal could be bad or the head loose causing a lot blown-sprinkler1of blow by. Try tightening the head, (yes, all this while the system is running). If none of this stops the excessive water, replacing the head and riser is the simplest solution. If the leak is around the stem or nozzle riser, you can take these head apart for cleaning. Perform this action with the water turned off. To avoid additional dirt in the system, its best to dig away the dirt from around the head, down to the connection otherwise dirty water will enter the lines. It’s important to remember to do your best job of keeping new dirt from entering the system as this will cause more blockage problems further down the pipe. TIP: Keep a couple of extra sprinkler heads around for spares and spare parts. Changing the head is lots less invasive and a 1 for 1 head swap out than trying to operate on the head in the dirt and water. You can also rebuild the removed head for future change-outs.
  2. If the head is not leaking inspect the pattern of the water spray. Different nozzles are designed with different patterns, so the spray could be limited by design to provide adequate coverage. There are too many nozzle patterns to discuss, but most importantly, look for a  nice clean even pattern. If you see breaks or weakness  in the pattern, the nozzle is probably dirty. Turn the zone off and unscrew the nozzle. There will be a  filter in the riser. Clean the dirt out of it. Also inspect the nozzle itself for very small pebble grit lodged in the sprayer. Use a toothpick or very small screwdriver to remove these particles. The last item may require 2 people. Run the zone without the nozzle installed, this will blow-out any dirt particles that are below the filter. Tell your partner to turn the water off and grab the riser before it stops releasing water. This will keep  dirt from re-entering the system. Re-install the filter and nozzle. Perform this same inspection with each sprinkler zone.   
  3. If necessary, (while the zone is running) adjust any partial pattern sprayers that may be near sidewalks or driveways to keep the water spraying on the grass. If you have parkway sprinklers that  are designed to water across a sidewalk (bad design)  to water grass or plants, you may be stuck with leaving it alone since cutting it back may cause an area to be dry.

Key Inspection Points and Action Items:   

  1. Look at your water meter for any slow leak that may be caused by your sprinkler system. Isolate the sprinkler valves to determine where the leak is.
  2. Run each zone, inspect each head for leaks, also look for a good pattern and good coverage. Cleaning the heads may be required.  
  3. Adjust the sprinkler heads as necessary to minimize water over-spray on no-porous surfaces (sidewalks and streets).
  4. Adjust your water cycles to match the season.