Walk the zone while it runs
Look for geysers, bubbling soil, heads that do not rise, misting, unusually wet areas and pavement overspray. The visible symptom may be several heads away from the actual break.
Compare the other zones
If every zone is weak, investigate supply, controller and system-wide causes. If only one zone is affected, focus on that valve and its downstream piping and heads.
Clean and compare nozzles
Debris can reduce flow or distort spray. Compare similar heads in the same zone and make sure plant growth is not physically blocking the pattern.
Do not solve coverage with excessive runtime
Running a weak zone longer can saturate the areas that still receive water while the dry area remains dry. Correct distribution first, then calibrate runtime.
Document before digging
Mark the wettest and weakest points, note recent landscape or fence work and photograph the zone. That information can shorten troubleshooting time.
We link the underlying source so property owners can verify the recommendation and read the technical detail.
UF/IFAS: Watering Your Florida Lawn