How to Replace a Rotor Sprinkler Head
There are two ways to go about replacing a faulty rotor. You can change out the entire body or just the guts of the existing spray.
Before you do either, most rotors come with a selection of nozzles. Install the nozzle now. It’s easier than kneeling in the dirt to do it later. If you are not sure which nozzle to use just match the old one.
To replace the guts you must have an identical model and brand. (There are exceptions but rare and not addressed in this article.) Simply unscrew the top of the rotor and insert the new rotor guts into the existing rotor body.
Replacing the guts of the rotor will eliminate digging the rotor completely out of the ground. Anything that avoids shovel work is a good thing. Instead pull the soil back from the rotor cap. Unscrew the cap, remove it and the parts, and replace with new.
To replace the entire unit you should gently dig around the rotor to loosen the soil and allow you to get a grip on the body. You may have to dig down to the connection, depending on the soil. Then simply unscrew the old, screw on the new.
If you are going to replace with a complete unit but a different brand, make sure the new brand is the same height. You don’t want to end up with a rotor too short to clear the grass or too high to mow over. A 4” rotor does not necessarily have the same dimensions in every brand.
A final step in rotor replacement is setting the fixed side and the angle of rotation. All rotors come with one side ‘fixed.’ This is the starting point the rotor starts from. The instructions will tell you which side is fixed. Then you adjust the rotation to cover the area needed.
A cut-off nipple is a threaded fitting that is attached between the rotor and the pipe fitting on the pipe in the ground. Pieces can be cut-off using a pipe cutter to allow you to position the rotor at the correct height. These are common.
You may have a swing joint connection. These will allow you more flexibility than a cut-off nipple. If you cut the cut-off nipple too short the cut-off nipple is now useless to you. So you buy a new one and re-cut. You can always save the incorrectly cut-off nipple for future use... but who needs the clutter. Another added feature which makes a swing joint appealing is its flexibility and durability. If you run over a rotor with a lawn mower or a car and have used a swing joint the risk of damaging the pipe or fitting in the ground is not really an issue because the material is flexible.