1) One zone won’t turn on (or won’t turn off)
Common causes: stuck valve diaphragm, debris in the valve, failed solenoid, cut valve wire, controller programming issue.
Quick check: If the zone runs when you open the valve manually but not from the controller, it’s often electrical (solenoid/wiring/controller). If it won’t shut off, suspect valve debris or a torn diaphragm.
2) Low pressure across multiple heads
Common causes: mainline leak, partially closed shutoff valve, failing pressure regulator, clogged filter (if applicable), too many heads/nozzles added to a zone.
What you’ll notice: heads that used to pop up now “spit,” rotate slowly, or don’t reach the intended distance.
3) A single head is geysering or pooling water
Common causes: cracked sprinkler body, broken riser, damaged swing joint, nozzle missing, mower/edger impact.
Pro tip: If the soil around the head is constantly soft, the leak may be below the head (swing joint) rather than the nozzle.
4) Dry stripes or “donuts” of brown grass
Common causes: misaligned heads, clogged nozzle screen, wrong nozzle size, head not popping up fully, spray blocked by growing turf/shrubs.
Easy win: Cleaning a nozzle and resetting arc/aim often fixes this in minutes—if the head and pressure are otherwise healthy.
5) Sprinklers misting (fogging) instead of throwing clean streams
Common causes: pressure too high, incorrect nozzle, worn nozzle, spray head mismatch in the same zone.
Why it matters: mist blows away in wind and evaporates faster, which wastes water and still leaves turf under-watered.
6) Water bubbling up in the lawn (not at a head)
Common causes: cracked lateral line, split fitting, root intrusion, freeze damage.
Best next step: Turn off irrigation immediately to prevent erosion and bigger washouts, then locate and isolate the zone or mainline section.
7) Backflow preventer leaking or squealing
Common causes: worn seals, debris, freeze damage, incorrect startup/shutdown steps.
Why it matters: backflow devices protect your drinking water supply from contamination. If yours is leaking after winter, don’t ignore it—have it inspected and repaired before heavy irrigation season.