CSLB C-27 Landscaping ContractorIrrigation SystemsMedium
A landscape contractor is performing a spring start-up for a residential irrigation system. After turning on the main water supply, the contractor observes that water is flowing from a sprinkler head in Zone 1, even though the controller is off and no zones are programmed to run. Which of the following is the most appropriate initial troubleshooting step?
- ACheck the wiring connections at the Zone 1 valve and the controller.
- BReplace the entire irrigation controller.
- CImmediately replace the sprinkler head in Zone 1.
- DManually turn the solenoid on the Zone 1 valve to the 'off' position or tighten it.
Show answer & explanationAnswer & explanation
Correct answer: D. Manually turn the solenoid on the Zone 1 valve to the 'off' position or tighten it.
If a zone is flowing with the controller off, it indicates the valve is mechanically stuck open, or the manual bleed screw is open. The most appropriate initial step is to check the valve itself. Manually turning the solenoid or ensuring it's tightened can often resolve a valve that is stuck open or was manually opened during winterization.
Why the other options are wrong
- A. Checking wiring is for when a valve *doesn't* open or close electrically; if it's flowing with the controller off, it's a mechanical issue at the valve.
- B. Replacing the entire controller is a drastic and expensive step, premature before checking the individual valve.
- C. Replacing the sprinkler head is unnecessary; the issue is the valve allowing water through, not the head itself.
Constantly Running Zone Troubleshooting
Diagnosing an irrigation zone that flows water even when the controller is not activating it, typically indicating a mechanical issue with the zone valve.
- Often caused by debris in the valve diaphragm, a faulty solenoid, or a manually opened bleed screw.
- Initial steps involve checking the valve itself before electrical components.
- Can lead to significant water waste if not addressed promptly.
Memory trick: Valve won't stop, even when controller's asleep? Check the valve's own keep!