How to Change an Irrigation Solenoid

An irrigation solenoid receives an electric impulse from the irrigation system and turns opens the sprinkler valve, supplying a zone with water. When the water zone needs to be turned off, the solenoid valve will receive another message and it will close.The purpose of these valves is to turn each zone on and off automatically. If a solenoid needs to be replaced, the zone it supplies will simply not turn on.

Step 1: Close the main water supply and shut off electricity

irrigation controller

It is very important that the main water line is closed before you attempt to work on a solenoid valve. If the main line is still open, removing the valve will cause a lot of water to shoot up from the now completely open space. Also, since you will be dealing with the electrical wiring of the irrigation system, it is a good choice to shut off the electrical supply so you don’t get shocked while connecting and disconnecting the wires.

Step 2: Locate solenoid and create working space

irrigation valve

A valve box covers the solenoid valve and wires, but if you just dig it out, there is a risk for breaking the wires or messing up the circuit. It is easiest to remove some dirt from around the valve in order to remove the valve box and create a work space that can easily be accessed.

Step 3: Disconnect and remove the solenoid from the valve

disconnect solenoid

After double checking that the electricity is powered off, follow the on and off wires from the installed solenoid to their connections, and disconnect them. It is important to keep these two wires separate and to never confuse them. Remove the nonworking solenoid from the work space.

Step 4: Replace the solenoid


This is the part where the on and off wires are very important. Connect the on portion on the solenoid to the on wire, and the off portion of the solenoid to the off wire. This  will complete the circuit to turn the valve when the electricity is on, so now you can turn the valve into its place. However, do not fill in the hole yet or return the valve box. You wouldn’t want to have to go back into the valve box if  the test is unsuccessful.

Step 5: Turn on electricity and water supply

Since you shut off the water and electrical supply, turn them back on in order to test the new valve.

Step 6: Test sprinkler system and make final adjustments

valve box

If your test is successful, put the valve box back over the wiring and fill the hole around it. Be sure not to get any dirt into the valve and wiring space. When you finish filling in the hole, the valve box should be flush with the ground so it doesn’t get run over by a lawn mower.