When water gushes freely from a sprinkler but stops when you turn off the sprinkler control or valve, the sprinkler head is loose or has fallen off, or the riser is broken.

To fix this, replace the head, the riser, or both. For a ground-level sprinkler, you'll need to dig down to where you can unscrew the riser from the threaded tee or elbow. Turn off the sprinklers before starting.

To replace a shrub head, just unscrew it by turning it counterclockwise. If necessary, hold the riser with locking-jaw pliers and turn the head with an adjustable wrench.

Lawn sprinklers, which are flush to the ground, are more difficult to grip and turn. To do this, use a universal head wrench.

First, dig down to the threaded tee or elbow, clearing away all surrounding soil so it doesn't fall into the pipes when you disconnect them. Unscrew the broken riser by turning it counterclockwise.

If a plastic riser has broken off inside the tee or elbow, tap a chisel into the broken piece, wedge the chisel against one edge, and turn it counterclockwise. Be careful not to damage the tee or elbow's threads.

Replace the riser with a new one of the same length. Flush dirt from the line by turning on the sprinkler valve for a few seconds before replacing the head.