Adjusting sprinkler heads ensures your lawn receives the exact amount of water it needs, preventing waste and promoting healthier growth. Proper calibration maximizes water efficiency by placing moisture precisely where the landscape requires it and minimizes overspray onto hardscapes like sidewalks and driveways. This maintenance task optimizes your entire irrigation system.
Essential Tools and Preparation
Before attempting adjustments, completely shut off the water supply to the irrigation zone to avoid accidental sprays and system damage. A standard flathead screwdriver is the primary tool for most adjustments, especially for modifying the water stream’s distance. Rotor-style heads often require a specialized plastic or metal adjustment key unique to the manufacturer (e.g., Hunter or Rain Bird). Needle-nose pliers can be useful for cleaning debris from filter screens or manipulating small components. Always inspect and clean the area around the head before moving any parts.
Adjusting Fixed Spray Heads
Fixed spray heads, often used in smaller areas, distribute water in a continuous, stationary pattern. Direction is adjusted by physically rotating the entire riser assembly or the pop-up stem. With the water off, grasp the top of the stem and turn it gently until the spray pattern is aimed correctly, utilizing the ratcheting mechanism to fine-tune the direction.
These heads feature a radius screw, also known as a deflector screw, located at the center of the nozzle opening, which controls the water’s throw distance. Turning this screw clockwise with a flathead screwdriver drives it further into the water stream, shortening the radius. Conversely, turning the screw counter-clockwise moves it out of the stream, allowing the water to travel its full intended distance. This reduction ensures the water lands just short of walkways or driveways.
Adjusting Rotor Heads
Rotor heads rotate to cover a larger area and require precise adjustments for both arc of motion and throw distance. The first step is setting the stationary right stop, the fixed point where the rotation cycle begins. To set this, rotate the turret by hand to the right until it stops, then turn the entire pop-up body at the base until the nozzle points precisely at the desired starting boundary.
The next step is adjusting the arc sweep, the range of motion between the fixed right stop and the adjustable left stop. Use the specialized key to engage the adjustment socket, often marked with plus and minus signs. Turning the key clockwise increases the arc, while a counter-clockwise turn decreases it. A full 360-degree rotation of the key typically changes the arc by 90 degrees, allowing coverage settings from 40 to 360 degrees.
Finally, the radius, or throw distance, is adjusted using an Allen key or flathead screwdriver inserted into the radius reduction screw on the top of the head. Turning this screw clockwise drives a pin into the water stream, deflecting it and reducing the throw distance, usually by up to 25 percent. Run the zone briefly while making arc and radius adjustments to immediately observe the effect on the water pattern and coverage.
Troubleshooting Common Adjustment Issues
An uneven spray pattern often results from a clogged nozzle or filter screen. If the water is not flowing uniformly, shut off the system, remove the internal filter screen located beneath the nozzle, and clean it. A head that fails to pop up fully usually points to low pressure or excessive debris within the riser seal.
If the radius reduction screw is turned too far clockwise, it can overly constrict the water flow, potentially leading to the nozzle being ejected by pressure. A fine mist or fogging effect suggests the operating pressure is too high, causing the water to atomize. While pressure issues are usually addressed at the valve, installing the correct nozzle for the system’s pressure rating can mitigate misting.