How to Tell if a Hunter Sprinkler Controller Is Bad?

Hunter sprinkler controllers may fail for different reasons and with different symptoms. First determine the nature of the failure. Determine if the digital display is active or blank. Hunter sprinkler controllers activate independent groups of sprinklers in different sections of the landscape. These groups of sprinklers are called "zones" or "stations".

If the digital display is blank you may not have power to the controller. Depending on the model, expose the wiring by swinging the controller open or removing the wiring cover. Turn on your digital multi-meter and select the AC voltage setting. Find the wiring tabs or screws that are labeled "AC." Touch the probes of your multi-meter to the AC tabs. You should get a reading between 22 and 25 VAC (alternating current volts.) If you have sufficient voltage and your controller has no digital display, then the controller is bad and must be replaced. If you have no voltage then your power supply transformer that is plugged into the outlet is bad and must be replaced.

If your digital display is active, turn the dial of the controller from setting to setting. If the display does not change as you turn the dial, power down the controller by unplugging it and removing the backup 9V battery for 5 minutes. Replace the battery and plug the controller back in. Turn the dial again between settings. If the display never changes, the controller is bad and must be replaced. If the display changes when the dial is turned, the controller should be working again.

Determine if one or all stations are failing by manually activating each station at the controller. If you have one or all stations not working on your sprinkler system, it could be one of several things. If a single station does not work (station 3 for instance) activate the failing station manually with the controller. Turn on your digital multi-meter and select the AC voltage setting. Find the wiring tabs or screws that are labeled "station 3" and the common wire labeled "C." Touch the probes of your multi-meter to the station 3 and C tabs. You should get a reading between 22 and 25 VAC (alternating current volts.) If sufficient voltage exists, the problem is elsewhere (field wiring or valve) and not in the controller. If the station 3 is manually active at the controller and you have no voltage, the controller is bad and must be replaced. Repeat for all failing stations.