One Sprinkler Head Leaks at Low Pressure: Valve Not Sealing

Symptom: Single Head Dribbles When System Is Off

If one head leaks at ~1/6 pressure after the system should be off, and it's the lowest head on that zone, the zone valve is likely not closing fully.

Why the Lowest Head?

Water seeks the lowest point. A valve that leaks even slightly will show water at the lowest head on the zone.

Confirm the Valve Is Leaking

1. Locate the automatic valve for that zone (usually in a valve box).
2. Listen closely: a faint hiss or gurgling indicates water passing through.
3. Feel the valve body: vibration or warmth suggests flow.

Fix Options

• Rebuild the valve: Replace diaphragm, spring, and clean ports.
• Replace the valve: Often faster and more reliable for older valves.

Resource

irrigationtutorials.com has brand-specific valve rebuild guides.

Do not replace the head—it's a symptom, not the cause.