Are the spray heads or rotor heads on your lawn sprinkler system constantly sticking up when they should be retracting back down?
Don't worry, this is a common problem and is most likely caused by one of a couple factors. First of all, what is the age of your sprinkler heads? Over time (anywhere from 3 years and beyond) the wear and tear on the risers will cause rough edges which will cause the head to stick up.
The more sandy the soil is, the quicker the risers will wear. The only way to fix this after the head is this damaged is to replace the head. However, there is another option available to prevent this from happening again. That would be to get sprinkler heads with stainless steel risers. They are a little more expensive, but will last much longer.
Flushing Out Your Lawn Sprinkler System
If you have a system that is pretty new and you are constantly having problems with the heads sticking, you could have dirt in your pipe. The dirt could have entered your system when you were repairing a break, or it could just be sediment from your well.
Sometimes, the heads can be easily cleaned by stepping down on the riser while the head is running. Let it pop back up, then step on it again. Do this a few times, then turn off the system and see if the head is still sticking.
If you have several heads with this problem, you may want to flush out your system. This can be done by removing the nozzles and screens on the spray heads and installing flush caps, then running water through the system. Flush caps come with the spray heads when you first buy them. If you don't have any, this can also be done by removing the head completely and pulling up the swing joint and then flushing.
The rotors will have to be flushed in that manner anyway. If your system is older and your heads are not installed on swing joints, then just make sure to dig around the hard PVC riser that the head was attached to, making sure that no dirt can flow back in the pipe while you are flushing.
You may also want to take the sprinkler heads to a water faucet and clean them out. Unscrew the inside of the head from the casing and rinse out both pieces. After you are done flushing the system and cleaning the heads, re-install the heads and run your system for about 10 minutes.
Then turn off the system and make sure all the heads went down. If some are still stuck, they may be beyond fixing and you'll just need to replace them. If you are in sandy soil, I would recommend rotors with stainless steel risers. Rotors cost anywhere from 3 to 5 times the cost of rotor heads. Spray heads are a lot less expensive and it is more economical to just replace them, rather than purchasing expensive steel risers.