An automatic sprinkler system takes the planning out of watering your lawn in addition to relieving you of moving sprinklers and timing when they run. Eventually, however, the sprinkler system may begin to spring leaks caused by freeze-thaw cycles or the chemistry of its underground environment. Sprinkler heads often show their age first, especially the kind of heads that pop up or oscillate. Repairing or replacing a sprinkler head is typically simple, but the first task is to isolate the passive device from the rest of the sprinkler system and shut it off.
Turn off the water at the main shut-off valve near the automatic sprinkler system's water source. The main shut-off valve is typically near an outdoor spigot and should have a switch or wheel on top that allows it to be operated easily manually.
Locate the zone valve that controls the target sprinkler head's group of sprinklers. Zone valves are located in wells in the yard and covered with metal or plastic plates. A sprinkler system has multiple zones, and so the zone valve nearest the target sprinkler head probably controls it.
Examine the zone valve's side for a manual control lever. Flip that lever to the "Off" position if the lever is present.
Disengage the solenoid if no manual control lever is present. The solenoid is in a tube that rises above the valve casing on the outflow side of the valve. Look for labels on the top of the solenoid chamber for specific directions to disengage the solenoid. Typically, though, disengaging it requires rotating the unit one-quarter to one-half turn counterclockwise.
Dig out the soil surrounding the sprinkler head. Unscrew the sprinkler head to repair or replace it. Cap the sprinkler head stub if you wish to remove the sprinkler head position from the sprinkler system, tightening the cap firmly with pliers cushioned with a piece of cloth. Do not overtighten plastic parts.
Open the sprinkler line in the reverse order that you closed it.