Troubleshooting a Sprinkler Zone That Shows Active but Delivers No Water

If your irrigation controller indicates that zone 1 is running but no water emerges from the sprinkler heads, follow these systematic checks to isolate the problem:

1. Verify Voltage at the Station Terminal

Use a multimeter to confirm the controller’s station terminal for zone 1 is outputting the correct voltage (typically 24 VAC). If voltage is absent or low, the controller or its wiring may be at fault.

2. Check the Flow Control Valve

Ensure the flow control on the valve itself hasn’t been turned all the way down, which would restrict water flow even when the valve is energized.

3. Inspect Timer Terminal Connections

Examine the wire connections at the controller’s terminal strip. Loose or corroded connections can prevent the signal from reaching the valve.

4. Check Wiring Between Timer and Valve

Trace the field wires from the controller to the valve box. Look for cuts, nicks, or disconnections that could interrupt the circuit.

5. Test the Valve Solenoid

With the water off, remove the solenoid and activate the zone from the controller. The plunger should retract cleanly. If it doesn’t, replace the solenoid.

6. Inspect the Valve Diaphragm

A torn or debris‑clogged diaphragm will prevent the valve from opening. Disassemble the valve and examine the diaphragm; replace if damaged.

Work through these steps in order, and update your findings if further troubleshooting is needed.