Pop-up sprinkler heads rise from the ground to water the targeted areas, then drop down again until it is time to water once more from tyhe connected sprinkler system. When the heads become worn they tend to get stuck in the watering (raised) position. If damaged, they can perform improperly, wasting huge amounts of water and killing nearby foliage. Replacing worn pop-up sprinkler heads easy a fairly simple task that can be accomplished in a few steps.
Check to be sure you have an in ground sprinkler system. If not, dig a 6 inch trench (6 inches deep, 6 inches wide) to all areas you wish to incorporate sprinkler service to, beginning from an exterior water source.
Lay 3/4 PVC into the trench. At every proposed sprinkler head location, add a three-way splitter to the PVC piping, with the extra hole pointing up towards the sky. Install (screw in) a 1 inch threaded PVC riser to this hole.
Connect the 3/4 PVC tubing to the water source. Put a PVC cap on the downstream end of the PVC tubing system.
Thread a pop-up sprinkler head onto the end of each riser. Back fill the trench with dirt. Test the system for functionality. If there is a problem with a sprinkler head later, it must be cleaned out or replaced (if worn).
Locate the sprinkler head that will be cleaned out or replaced. Dig up the lawn surrounding the sprinkler head in an 8 inch circle, using a hand garden trowel. Set the turf or sod aside for later use, and keep the dirt in a small neat pile.
Dig down about 5 inches and be cautious not to damage any plastic water lines you encounter. If your existing pop-up sprinkler head measures 6 inches tall or more, the water line is probably fairly shallow, and may utilize a side feed mechanism.
Continue to dig down until you have uncovered the water supply line, as well as the base of the pop-up sprinkler head. Hold the water supply line with one hand, and unscrew the pop-up sprinkler head body with the other hand.
Compare the old and new pop-up sprinkler heads. They should be similar in design and shape, with the same diameter threading located at the bottom of each pop up. Clean the threads on the water supply line, then apply plumber's tape to the clean threads. Screw the new pop up sprinkler head onto the supply line threads. Place the sprinkler head vertically in the hole.
Turn on the sprinkler system for that zone (if a zoned system) to be sure no dirt is clogging the sprinkler head. If it pops up as expected, turn the sprinkler system back off. Hold the sprinkler head slightly below the lawn surface in the vertical position, and bury with the dirt previously removed. Replace the turf or sod in a circle around the sprinkler head.