A home improvement show on PBS or HGTV would never devote an entire show to the replacement of an underground sprinkler head. They would give it 30 seconds, something like this:
“Sometimes these will get clogged or just broken off. If that happens, just unscrew it and screw another one back in its place and you’re done.”
When I get my show, I will pay less attention to covering a complete job like installing an entire system than to fixing things in the real world. For example, here is my script:
“Sometimes a sprinkler head will get clogged or broken off. When that happens allow about an hour or two to deal with it. First dig a hole around the broken head. You’ll see why in a minute.
Notice how when I unscrew the old one, loose dirt falls down into the hole. This will fall into the pipe and clog the new head when you put it in. Also, when you screw the new one in on top of that dirt, the chances are pretty good that you’ll cross-thread the new one and you may or may not get a good seal. In that case, you’ll have to dig out around it anyway to replace the head and the cross-threaded pipe. In all likelihood, the contractor who installed the system glued the entire thing together with PVC cement so you’ll have a real job on your hands then. So we just dig out around it to begin with.
To get through the grass, you’ll need your hand cultivator but it’s out in the back yard and you probably don’t want to go back there to get it since the dogs will see and start barking to be let in. You don’t want that since you’ve started good and early in order to avoid the forecasted heat index of 110 degrees. So just use a common camping hatchet. That’s terrible for the blade but you can always re-sharpen it later on when it’s cooler – say in November.
Now, we’ve gotten the hole dug and notice that it has to be at least a foot in diameter even though the head itself is only about an inch and a half in diameter. You can’t dig a hole smaller than your shovel so now you have lots of room to work. Dig down to the pipe, clean off the threads very carefully and screw on the new head.
Remember, there’s mud stuck in there from earlier so now you want to unscrew the mechanism and take it out. Oh, and make sure you buy a replacement that allows you to take it apart. Anyway, now go out into the back yard and figure out how to manually turn on that zone for that sprinkler head. The installer won’t have labeled anything so this will take some experimenting.
As each zone comes on, try to figure out if it’s the one you want or not which is tricky since the controller is in the back yard and the sprinkler head you’re fixing is in the front yard. The dogs will bark maniacally as each head pops up out of the ground and squirts them even though it’s been doing this twice a week for their entire lifetimes. As far as they are concerned, their frenzied barking is totally effective since the heads eventually retreat back underground. In their minds, that was a job well done. But this means you can’t tell by listening for splashing whether the correct zone has been reached.
Finally, you’ll find it and the mud will be blown out. If you happen to be standing next to it when that happens, just throw that shirt away – mud stains will never really come out. This soil is red clay down about three inches (6 cm) and it stains like dye. Now, screw the mechanism back in (after turning the system off).
Fill the dirt back in (it won’t all fit by the way since dirt expands when you dig it but over time it will fill in – with what I don’t know but it all seems to work itself out in a couple of days. Put the grass clump back on top. This won’t grow and will in fact die but it will cover the hole until the new stuff grows back which it does pretty quickly since it’s right were a sprinkler head is.
That’s it – you’re all set. Now go back to the back yard and kick the barking dogs.”
Or something like that.