An irrigation system should work for many seasons without trouble, but eventually due to wear and tear you will have to repair or replace some of its parts. Fortunately, sometimes it’s as simple as replacing some sprinkler heads to return your system to full working condition. Here are some common reasons for replacing sprinkler heads.
Sprinkler Heads Not Popping Up or Retracting
Most pop-up sprinkler heads have springs that push them up or pull them back into the ground, depending on the water pressure. Sometimes sand gets stuck in the gap between the riser stem (plastic or metal tube above the sprinkler body where the nozzle is attached) and the cap (the part that screws onto the sprinkler body) of the sprinkler, jamming the head.
There are several things you can try to fix a sprinkler head not retracting or only partially popping up. First, turn on your sprinkler system, and push the sprinkler head gently with your foot so the head is pushed all the way back down into the body. Release it so it pops back up. Repeat this four or five times to loosen and flush out any sand caught between the riser and the cap.
If that doesn’t work, turn off the water and try pulling the riser up with your hand. There should be some resistance due to the retraction spring, but the riser should move up and down easily without hanging up or catching. Sometimes the riser and the seal become so badly scratched by sand that the rough surface prevents the riser from moving smoothly in and out of the sprinkler body. Your only solution for this is to replace the sprinkler head.
Excessive Blow-By of the Sprinkler Riser
Blow-by is the small amount of water that squirts out of the gap between the riser stem and the cap when the riser comes up. A small amount of blow-by is normal. It helps clean dirt and grass off the riser as it pops up and down, and lubricates the seal. A lot of water squirting out is not normal, and in this case you will need to replace the sprinkler head.
Leakage Between Riser and Cap When Riser Fully Extended
There shouldn’t be any water leaking between the riser stem and the cap when the riser is completely up. To check, turn on the sprinklers and inspect each one for leaks only when the riser is fully extended. If the riser doesn’t come up all the way, pull it up with your hand, and hold it there if it won’t stay by itself. You need to check all the sprinkler heads, because if one near the zone valve is leaking, it can prevent a different sprinkler further from the valve from completely popping up. When the sprinkler is fully extended, leakage indicates one of the following: the riser seal is bad, the riser is scratched, or the cap is scratched. You will need to replace the sprinkler.
Sprinkler Heads Too Low in the Ground
Sprinkler heads installed too low in the ground aren’t able to rise above the ground and grass level or the level of any surrounding plants. The water then doesn’t spray properly, leading to coverage problems and flooding around the heads. Dirt is more likely to get into sunken sprinklers causing retraction and other mechanism failures. In such a case, replace the sprinkler and install at the correct height for the area.
Over time, sprinkler heads will also settle into the ground due to the natural compaction of soil, and build-up of decomposing leaf matter, grass clippings, etc. Always inspect your sprinkler heads to make sure they’re sitting at the correct level.
Broken and Damaged Sprinkler Heads
These obviously need to be replaced. Sprinklers that are too high (due to incorrect installation or soil erosion) or too low are tripping hazards, and can be damaged or broken when someone trips on them.
Sometimes creatures looking for a drink will cause damage by chewing on the heads and nozzles, especially during droughts. Lawn mowers, as well as cars, can destroy sprinkler heads by running over them.
When replacing broken sprinkler heads, consider using an appropriate swing riser assembly. These can help protect your rotor or spray sprinklers from future damage when run over or stepped on. Your irrigation professional can help you with this.
Different Sprinkler Head Types in Same Valve Zone
While you can mix different brands in the same zone, don’t mix the type of head because they have different flow rates. Rotor heads, spray heads, matched precipitation etc all throw water at a different rate. Mixing them in the same zone will waste large amounts of water, and create a huge imbalance that causes overwatering and underwatering. Choose the type of sprinkler head you want in that zone, and replace the others.
If your original brand isn’t available, find one with the same specifications, or change all the sprinklers in that zone to match. Changing all of them in this case is the better option, because if the original brand isn’t available, the sprinkler heads are old, and due for a change.
Updating Due to Changing Landscape
Your landscape changes over time, and in turn, as your plants and trees grow, their irrigation requirements also change. You might also replace these plants, and add others, and your irrigation system has to keep pace in order to provide proper coverage. This will involve moving and adding new sprinkler heads, as well as raising and lowering them.
Rotor Sprinkler Won’t Rotate Properly
A rotor sprinkler head not rotating at all, or only in one direction, then stopping, can be caused by too little water pressure. However, if the water pressure is adequate, the head could just be clogged. Take the sprinkler apart, and wash away any debris or dirt. Next, clean the filter. If cleaning doesn’t work, you’ll have to replace the sprinkler head.
Sprinkers Continue to Drain at Bottom of Slope When System Off
This phenomenon is known as low head drainage, and it occurs when you have water flowing from the sprinklers at the lowest elevation after the system is shut off. It may take several hours, but the runoff stops after the pipes are fully drained. This can occur in an elevation change of fewer than six inches. Not only is it a waste of water, but it can lead to landscape erosion, unsafe conditions on sidewalks, and pooling around sprinkler heads.
You can fix low head drainage by installing sprinkler heads with check valves. Check valves will prevent the water from draining out of the pipes through the lowest sprinklers, and are available as an option on all major brands. They don’t cause any drop in performance of the sprinklers, and work by closing and holding water in the pipes when the sprinkler system is off. You can buy retrofit kits (although they’re hard to find), to add a new internal check valve to most major brands of sprinklers. However, most professionals just buy a new sprinkler head with a check valve and replace the old one.
Call Smart Earth Sprinklers now and take advantage of our seasonal discounts for replacement of all your sprinkler heads. Call us today at (512) 694-1147.