There are a few reasons why you might want to test the serviceability of any of your solenoid coils contained within your irrigation system.

• Constant water flow: The solenoid may stick open, allowing a trickle or full stream of water to move through the sprinkler, even when the system tries to shut it off.
  • Check out STATION STAYS ON – VALVE NOT CLOSING…
• No water flow: The solenoid may not be actuating at all, resulting in valves that will not open.
  • Check out STATION WON’T TURN ON – VALVE NOT OPENING…
• Water leaks: High pressure from a broken or faulty solenoid stresses your sprinkler system, causing minor or large cracks and leaks.
  • Check out IDENTIFYING WATER LEAKS
• Low water pressure: With low pressure from a bad valve solenoid, you’ll see dry, brown spots develop on your lawn because of inadequate, uneven watering.
  • Check out TROUBLESHOOTING LOW PRESSURE
• A clicking noise from the solenoid when the system is running, may indicate that the solenoid is attempting to open but cannot fully do so.
  • Check out DIAGNOSING ELECTRICAL ISSUES

This article assumes that you understand BASIC MULTIMETER IRRIGATION PRINCIPLES, if you’re not fully versed please check it out now.

The first step will be to verify that the controller is supplying ~24VAC at the terminals, activate the station you’re testing and with the Multimeter set to VAC place one probe onto the Common Terminal and the other onto the Station Terminal, you should get a reading of ~24VAC. If not begin TROUBLESHOOTING A FAULTY IRRIGATION CONTROLLER.

Next we will verify the solenoid is ok and electrically connected to the controller. With the controller turned to ‘Off” and the Multimeter set to Ohms place one probe onto the Common Terminal and the other probe onto the Station Terminal, this should return a reading of ~25-35 Ohms, if not then there is likely a broken line to the solenoid coil or the coil itself is dead and requires replacing.

Now we will test the Voltage at the Coil by activating the station in question and with the Multimeter set to VAC place one probe onto the Common Line and the other onto the Station Line, you should get a reading of ~24VAC. If not then we will be looking at either replacing the control wire or using any spare wire that my be available in-sheath.

We then test the Ohms at the Coil, making sure the controller is set to ‘Off’ and with the Multimeter set to Ohms place one probe onto the Common Line and the other onto the Station Line, you should get a reading of ~25-35 Ohms. If not, the coil itself is dead and requires replacing.