Saturday, May 26, 2007

One sprinkler zone not working

Got a zone that is not turning on? All you need to do if figure out if it is the timer, wire, or valve at fault. The way you do this is by a simple process of elimination. First off, you will need a volt meter (get one cheap here). Set your volt meter to DC Volts.

First, go to the controller and turn on the zone in question and see if you have 24 Volts at the zone valve in question by touching the leads from the volt meter to the wires at the solenoid (make sure your wire nuts are tight and the connection is free from corrosion). If you have 24 volts here, then you have a solenoid or valve problem. Now, disconnect the solenoid wires from the timer wires and turn your volt meter to OHM's. Place your leads on the solenoid wires- you should get a reading of 20 to 60 ohms. If you get 0 your solenoid has a short in it and needs to be replaced. If the solenoid checks out, remove the solenoid and check the plunger in the bottom of the solenoid for dirt or debris. Also make sure the tiny hole where the solenoid screws into the valve is not clogged. If it is, poke a small paper clip into the hole to remove the debris. If this checks out, take the top off of the valve and check the diaphragm for holes or wear. If it has holes or shows signs of wear, replace the diaphragm. If it looks ok, check inside the body of the valve for rocks or debris.

If you did not get 24 Volts at the solenoid, go to your controller and find the wires that go to the zone in question. Turn on that zone. Set your volt meter for DC volts and check the connection for 24 volts. If you have 24 volts at the controller with the zone on, your wire to the zone valve has a short in it and you will need to run new wire to the valve (unless your original wire is a multi-strand sprinkler wire with an extra set of wires in it, in which case you can simply use the extra set of wires).

If you have no voltage at the zone valve or controller, you have a controller issue. If it is a modular controler, pull out the module and re-seat the module, then try to get a reading again. If you still have no voltage, replace the station module. If nothing still, replace the controller.


Anonymous said...

I have a sprinkler zone where where water is backing up and trigger my backflow preventer several times during a cycle. Any advice on what might be causing the problem?

Anonymous said...

Correction: Voltmeter should be set to AC Volts, NOT DC Volts when checking the controller voltage.

Rich said...

This is a great reference that has helped me solve an issue! Thank you so much.