How Do Oscillating Sprinklers Work?

By Brian Mounts | May 26, 2020
how do oscillating sprinklers work

Oscillating sprinklers are one of the most common home lawn and garden sprinklers available and understanding how they work is important, so you can pick the right one and maintain it for years to come.

There are some stark differences between the oscillating and the impact sprinklers and how they work. For instance, when you turn on the hose to an oscillating sprinkler:

Water pressure from your hose flows through the base of the unit and spins a small internal water wheel, which turns a series of gears, that activates the cam to rotate, which controls the movement of the aluminum bar with the spray nozzles. 

The following guide will go into greater detail so you can understand a little bit more about how an oscillating sprinkler works.

How does an Oscillating Sprinkler work?

Oscillating sprinklers are simple devices that power themselves through basic water pressure from a hose.

The aluminum tube that contains the sprayer bar is the part that ‘oscillates’ moving back and forth to water the lawn as it sprays in a fan shaped pattern.

It is a simple device that is powered by the water flowing through the spray arm and it then sprays water evenly out of the holes or nozzles in the aluminum bar.  This heart-shaped cam keeps the aluminum bar moving smoothly from left to right which gives the oscillating sprinkler the ability saturate the ground evenly within its specific coverage area.

The heart shaped cam assists the sprinkler to have an even flow of water in all directions, if it was simply a circular crankshaft it would cause the spray pattern to be heavies on the sides and not as much water in the center position.  The ability to cover large areas of lawn means that while a simple device they are one of the best types of lawn sprinklers available for sale today.

Inside the Oscillating Sprinkler

If you were to cut open the plastic base for an oscillating sprinkler you would see a series of plastic gears.  These gears are the power source for moving the cam back and forth to oscillate the aluminum bar.  As the water enters the sprinkler base it initially makes a quick pass through a simple turbine or water wheel that powers a series of gears that turn and provide the necessary power to make the device work and spray the water evenly.

The Differences Between Oscillating & Rotory Sprinklers

Can an Oscillating Sprinkler Get Stuck?

Yes, an Oscillating sprinkler can get stuck at times.

The reasons for sticking are generally pretty straightforward and there is common fixes for the issues. It might get stuck because of a few reasons which we might discuss here:

  • First check to confirm that your hose has water pressure. Unhook the hose from the sprinkler and turn it on and check if the water is flowing at a good speed.  If the water is not coming out of the hose, maybe there is a kink in the line somewhere you don’t see, the water line is not turned on, or something is wrong with your outdoor faucet.
  • Secondly, it might be stuck because of a large obstruction. If the device is new check to see if there is tape or any coverings from the packaging
  • Third, it may have something stuck inside that is preventing the water from flowing. Open up all of the knobs that unscrew and look inside to see if you can see any internal blockages.
  • Fourth, if the water is flowing fine from the hose, but not really coming out of the nozzles on the oscillating arm the sprinkler could have built up a heavy layer of minerals from hard water. To clean the spray nozzles, with the spray nozzle clean out pin and push through each of the holes.  You can also remove the bar and soak the it in a calcium and lime remover or vinegar to loosen the mineral deposits and rinse with clean water.
  • And last but not the least, sometimes the cam holding the oscillating part together damaged, this is one of those scenarios where it may be time to start looking for a new oscillating sprinkler as finding the parts may not be easy and getting someone to repair it may take more time than it is worth. Most oscillating sprinklers will last a long time and are cost effective so getting replacement parts for components may be more trouble than it is worth.

While these may not cover every problem for why an oscillating sprinkler could stop working, it does cover most of the common issues.

How to Adjust an Oscillating Sprinkler

It is important to adjust the oscillating sprinkler to fit your lawn and garden.  With the right placement and the correct settings you will be able to ensure that your sprinklers are spending the majority of the time hitting the right spots and not the neighbors fence, your driveway, or other places that you don’t intend to water.

Basically, an oscillating sprinkler has a dial knob near the end that connects to the hose that provides you with options for controlling the flow of water out of the spray nozzles. Generally, you will find three modes or a dial that goes up and down for several different spray patterns.

  • Right Side– You can set the mode to disperse the water from the spray nozzles from the right side of this device only. This will allow you to control the water dispersal in a tight spot where you don’t want to water the house or the driveway.
  • Left Side– This is like the right-side mode but just reversed. It allows you to spray water towards the left over a larger distance.
  • Center Mode – You can choose the “center” or “middle” mode. This is the setting that will provide the most balanced spray pattern and is the ideal setting when you are trying to get maximum coverage over a space and do not need to control the spray pattern.This may limit the spray pattern some if you have a fourth option for a full mode.
  • May Include Fourth Option– This mode isn’t in the list of three modes because it usually is taken up by selecting nothing. This is the “full” or “automatic” or “natural” mode. This allows you to throw the water in all the directions up to the maximum distance that your model can throw it.

A Few Final Words

The oscillating sprinkler is an excellent option for homeowners that need to water their lawn and gardens.  It is robust enough last for many seasons and most are designed to be easily maintained.

While the gears on the inside may be intricate, they are protected and rarely need to be cleaned of a jam caused by debris.  If you keep your hose clean and not sitting in mud, there is very little chance of causing an issue to the internal working of the oscillating sprinkler giving them a long lifespan.

Knowing how an oscillating sprinkler works will allow you to know fine tune the spray pattern that you set it up with and will ensure that your yard is adequately watered without being inefficient.

Keep the aluminum bar and spray nozzles clean by doing an annual cleaning to prevent the buildup of minerals is important if you live in an area with hard water.  Aside from this there is very little maintenance required to keep a sprinkler lasting for a long time.

Put it away in the fall so it doesn’t sit outside in the freezing cold all winter and you will have a great sprinkler to take out of the garage in the spring so you can water as needed.