CSLB C-27 Landscaping ContractorIrrigation SystemsMedium
A landscape contractor is troubleshooting an irrigation system where one zone consistently fails to turn on. Upon inspection, the contractor finds that the solenoid on the zone valve clicks when activated, but no water flows. All other zones are operating correctly, and the mainline has adequate pressure. What is the most likely cause of this issue?
- AA clogged diaphragm or a stuck plunger inside the valve.
- BThe main water shut-off valve is partially closed.
- CA faulty irrigation controller output.
- DA broken wire between the controller and the solenoid.
Show answer & explanationAnswer & explanation
Correct answer: A. A clogged diaphragm or a stuck plunger inside the valve.
If the solenoid clicks, it indicates that it is receiving power and attempting to actuate the valve. However, if no water flows, it suggests a mechanical issue within the valve itself, such as a clogged diaphragm or a stuck plunger that prevents the valve from fully opening and allowing water to pass through.
Why the other options are wrong
- B. If the main water shut-off was partially closed, it would likely affect all zones, not just a single zone.
- C. A faulty controller output would prevent the solenoid from clicking in the first place.
- D. A broken wire would prevent power from reaching the solenoid, thus no click would be heard.
Valve Mechanical Failure
When an irrigation valve's solenoid clicks but no water flows, it typically indicates a mechanical obstruction or failure within the valve's internal components, such as a clogged diaphragm or stuck plunger.
- Solenoid clicking confirms electrical function.
- Lack of water flow points to internal valve issue.
- Common issues include clogged diaphragms or stuck plungers.
Memory trick: Solenoid clicks, but water sticks? Internal valve tricks!