Sprinklers that aren't spraying properly can result in dead spots in the lawn. Examples of faulty spray include inconsistent flow, spraying in the wrong direction, spraying weakly, or failing to spray at all.
1. Test for Issues
Repairs can't proceed until the location of the exact problem is identified. This is done by running each sprinkler zone individually and checking the heads to see which ones are malfunctioning. Landscape flags are then placed next to any sprinkler head that is spraying weakly, failing to pop up, or spraying unevenly or out of alignment. The flags allow the problem heads to be found easily once the water is shut off.
2. Clean the Heads
Sometimes the simplest repair is to simply clean out the sprinkler valve heads. Dirt, grass, and other debris can get lodged in the spray openings. This obstructs the flow of water so it may not spray out properly. The heads can be removed and rinsed out, and dirt can be poked out with a toothpick. After cleaning, the heads are replaced, re-aligned, and tested to make sure they are working well.
3. Replace the Valve
If cleaning fails or if the valve heads are badly clogged with dirt, then it's time to replace the heads. Fortunately, sprinkler heads aren't very expensive or difficult to replace. Just make sure that the style of the new sprinkler heads matches the old one. New heads will need to be properly aligned to ensure that the spray is properly covering the lawn area targeted by the sprinkler.
4. Repair the Line
A broken line often has other issues beyond weak or non-existent spray from the sprinkler heads. You may notice a soggy area on the lawn, which will be near where the line leak is located. If you aren't sure where the possible leak may be, it is likely along the stretch of line just ahead of the first sprinkler in the zone that is malfunctioning. The line must be dug up and replaced with a new length that doesn't have any damage.
5. Verify the Pressure
Pressure issues can be spotted easily — the first few sprinkler heads will likely spray with more force, and then the force will gradually reduce as you move further down the line. In some cases, the pressure fluctuates, which causes the force of the spray from the heads to fluctuate. Pressure issues can be fixed by replacing the pressure regulator on the line.
For more info, contact a local irrigation contractor.