Adjust the oscillating sprinkler knob to determine the oscillation range.
An oscillating garden sprayer, or sprinkler, comes in many forms. The sprinkler can be installed underground, laid on top of the ground, spiked into the ground or moved across the ground. Any of the models can fail to oscillate, depending on its spray head settings.
Impact Sprinkler
If the impact head rotates continuously in only one direction instead of oscillating back and forth, the trip pin might be raised. At the base of the sprinkler head are two trip collars, which set the boundaries for edges of the watering area when adjusted. The trip pin is lowered between the two trip collars to activate the oscillation setting. If the trip pin, which is a skinny piece of metal located just above the trip collars, is lifted out of the range of the trip collars, the spray head turns in only one direction. Water pressure that is too high or too low prevents the impact spray head from turning at all. Insert a pitot tube pressure gauge close to the nozzle within the water stream to determine a reading, and adjust the water source accordingly.
Oscillating Sprinkler
An oscillating sprinkler is placed on the ground and sends a horizontal fan of water from one side of the lawn to the other. The oscillating sprinkler can be set to stay in only one position or to water the lawn partially using a control knob located on the sprinkler base. If the sprinkler is spraying in only one direction, select a setting on the knob so that the spray head oscillates over the desired watering area.
Rotor Sprinkler
Usually installed underground, the rotor sprinkler pops up to water the lawn when activated by a irrigation controller or an open water valve. On top of the spray head are a number of adjustment slots that control the water stream of the sprinkler. One of these slots, usually referred to as the arc adjustment slot, controls the oscillation range of the sprinkler head. The sprinkler comes with an adjustment tool or is sometimes adjusted with a screwdriver. If the sprinkler rotates in only one direction, it might be set to 360 degrees, which causes it not to oscillate back and forth. Use the supplied tool to adjust the arc or spray range of the sprinkler.
Traveling Sprinkler
A traveling sprinkler moves along a laid-out water hose, which also feeds it, and features two spray arms, which spin, propel the sprinkler and water the lawn. If the two arms aren't adjusted correctly, the sprinkler won't move and the arms won't spin. Confirm that the arms are adjusted to the same angle from the ground but in opposite directions. Also adjust the arms so that the they don't hit the base of the sprinkler.
