How to Troubleshoot an Irrigation Zone Valve

Tighten the solenoid knob on top of the valve by hand, if the connected sprinklers fail to turn off. If the solenoid knob was opened manually, then the controller is unable to shut off the valve. Twist the bleed screw, located an inch or two in front of the solenoid, until it's closed, as well.

Unscrew the solenoid completely, remove it and lift out the O-ring below, if water dribbles through the sprinklers after the valve is shut off. Wash the O-ring off with water and clear any debris with your fingers. Do not apply oil or cleaners to the O-ring, unless the directions allow it. If the O-ring is damaged, replace it.

Twist the knob on the irrigation controller to "Auto" or "Run" if the valves don't turn on as scheduled. Even if the schedules for all valves and programs are set within the controller, they aren't active until the timer is set to "Run."

Pull the lid off of the valve manifold box to uncover the underground valves. Unscrew the watertight splice connectors from the sections of bunched wires connecting the valves to the irrigation controller wire. Confirm that each wire is stripped a half-inch and is touching the wires that it's bunched with. Pair a wire from each valve with the white irrigation wire. Pair one color-coded irrigation wire with one wire from the irrigation valve. Screw the watertight splice connectors back onto the paired wires and replace the valve manifold cover.

Open the irrigation controller panel to expose the irrigation wire terminals, if some valves turn on and others don't. Confirm that the color-coded wires paired with the valve wires are the same wires that are used in the controller terminals. If they aren't, pull the wires from the terminals and insert the color-coded valve wires into the terminals. Confirm that all wires are stripped a half-inch. Remove the white common wire from the "Common" terminal and reinsert it to confirm a secure connection.