One head that stays low is often dirty, damaged, tilted, or buried. Several heads that stay low point toward low zone pressure, a restriction, or a leak rather than multiple simultaneous head failures.
Match the pattern before opening anything
| Possible cause | Best clue | First check |
|---|---|---|
| Debris around riser | One head sticks or retracts slowly | Flush and clean around the stem |
| Head installed too low | Grass and soil block the cap | Expose the body without stressing pipe |
| Broken riser seal | Water gushes around the stem | Compare replacement body and nozzle |
| Zone pressure problem | Several heads fail together | Use the one-zone low-pressure guide |
Check these in order
- 01
Check how many heads are affected
One affected head favors a local mechanical problem. Several affected heads require a zone-level pressure and leak check.
- 02
Clear the cap and stem
With the zone off, remove grass and compacted soil around the cap. Hold the stem up only as the manufacturer permits and rinse loose grit away.
- 03
Inspect for side leakage
Run the zone briefly. Excess water around the stem, body, or riser connection indicates a damaged seal or fitting that cleaning will not fix.
- 04
Match the replacement
Keep the same inlet size and compatible nozzle family. A higher-flow nozzle may make the entire zone perform worse.
- The head is next to buried utilities, hardscape, or large roots.
- Several heads remain low after nozzle cleaning.
- The connection below the head is cracked or misaligned.
Sources and review notes
General maintenance logic is checked against EPA WaterSense outdoor irrigation guidance. Product controls and disassembly steps vary by model; use the current manufacturer manual for your exact valve, controller, or sprinkler head.
Published and last reviewed: August 26, 2026