Why won't one of my sprinkler zones turn on?

Test the zone by hand first

A zone that will not start has one of four problems: the controller is not telling it to run, power is not reaching the valve, the valve itself is stuck, or water is not reaching the valve. You can sort out which in about ten minutes with no tools beyond a screwdriver, and it saves a service call that would only start with the same test.

Start at the controller. Rain Bird says to set your controller to manual watering mode to test each station individually.^[1] Run the dead zone by itself and watch whether the heads pop up. Then run a zone that works for comparison. If the dead zone does nothing and the others are fine, the problem is local to that zone. If several zones are dead, look at the main supply and the controller before the valve.

While you are there, make sure the schedule is real: check that the date and time are correct.^[1] A controller that lost power and reset can skip a program without any sign on the lawn until the grass browns.

Check the water supply

If a zone is slow or weak instead of dead, the cause may be flow, not electricity. Rain Bird's valve guide lists several: the flow control stem is turned all the way down,^[2] too many sprinklers are operating at one time,^[2] or there is an obstruction in the mainline pipe.^[2] For a valve that does nothing at all, its guide says to locate main gate or master valve and open it.^[2] If the whole system was shut off for winter and you restarted it, a gate valve or the main shutoff that was not fully reopened is a common culprit.

Open the valve by hand

Most home zones are run by an automatic valve in a plastic box in the lawn, usually with a green lid. Open the lid and look. EPA advises checking the connections inside valve boxes and that the valves can shut.^[3] Water pooling on the surface can be a sign of an underground leak.^[3]

The valve has a built-in manual control. On Rain Bird valves, you turn the solenoid handle counter clockwise 1⁄4 to 3⁄4 turn or until you hear water flowing through the valve.^[2] Go to the zone and see whether the heads come up. Then close it: only hand tighten the solenoid to close the valve.^[2] Over-tightening can damage the seat.

The result tells you where the fault is. If the heads spray when you open the valve by hand, the valve and the pipe are fine and the problem is on the electrical side, in the controller or the wire. If nothing comes up even by hand, the problem is water supply or the valve itself. Other brands work similarly, so check the label on the valve and the maker's guide.

When the valve works by hand but not from the controller

Rain Bird's order of checks is to check the controller for output power to the valve.^[2] That needs a multimeter and some comfort with low-voltage wiring, and it is where most homeowners should stop. The guide's conclusion is the one to remember: if output is detected at the controller, but no input is detected at the solenoid, then a power wire is broken or damaged.^[2] A buried wire cut by a shovel or aeration is the usual cause, and finding the break needs a locating tool.

If power does reach the valve, the solenoid is next. Rain Bird's test is to swap solenoids with the next valve, and says: without cutting wires, swap solenoids with the next valve (if present). If other solenoid operates valve, replace solenoid.^[2] Turn the water to the system off before you unscrew a solenoid.

A solenoid that has simply gone sticky can sometimes be revived. The guide lists dirt as a cause: dirt is interfering with proper solenoid operation.^[2] The fix it gives is to turn off the water supply and turn the solenoid counter-clockwise to remove and flush solenoid seating bowl in bonnet with clean water.^[2]

Stop and call a pro if

• The zone does not run by hand either. The diaphragm, the supply or a blockage in the pipe is involved, and that means opening the valve or the line.
• There is power at the controller but none at the solenoid. That points to a broken wire, which has to be traced and spliced with waterproof connectors.
• A swapped solenoid still will not open the valve. The valve needs servicing or replacement.
• Several zones are dead at once, or the controller shows nothing at all. Look to the controller or main supply.
• You see pooling water or a soggy patch near the valve box. That suggests a leak under the lawn. Contact Virginia 811 before you dig.^[4]

Getting help in Virginia

If the repair grows beyond one valve, see what sprinkler repair costs in Virginia, whether to repair or replace a system, and how to replace a broken head. Browse more irrigation answers or irrigation businesses.

When you would rather hand it off, describe the sprinkler problem once and licensed local contractors can quote it.