Maintain Your Old Sprinklers
Sprinklers are an expensive addition to your home, but well worth the investment. They pay for themselves over time by saving on your water bill, as you'll no longer be overwatering your lawn or garden with a hose. Taking good care of your sprinklers will ensure that they last for many years.
The best way to maintain your old sprinklers is catch a small problem before it becomes a big one. Examine the heads at least a couple of times a year. Immediately replace any broken sprinkler heads. This will avoid you watering the area right around the head with a gushing stream of water each time you run your sprinklers.
Replace Broken Heads
If a sprinkler head does get broken, it's not difficult to replace. You'll need to carefully dig around the head deep enough so that the riser it's attached to is clear of dirt. You don't want dirt to fall into the pipe once you have the head off. Unscrew the broken head and screw on a new one. Then, screw in the spray nozzle. Broken sprinkler heads waste water, which is bad for the environment and your wallet.
When freezing weather is coming, drain your sprinklers completely. Use your manufacturer's instructions on how to properly drain the system or hire a professional. While the pipeline should have been buried at least 6 inches below your area's freeze line, water inside the heads can freeze and crack or break them. Don't take the risk of any connecting parts of the water line freezing and breaking. Be sure and drain thoroughly as soon as cold weather comes and then you won't have to worry about doing it in an emergency.
If you're concerned about the water flow, place cans in various places and check them after running sprinklers. If cans in a certain area have little water in them, check the heads in that area specifically. Even without this problem, you may want to make a habit of cleaning your sprinklers once a year to prevent this. Remove the sprinkler heads and let them soak in water. Clean the risers and remove any dirt or debris inside the sleeve where the heads sit. Use a stiff wire to clean the heads if necessary. Then replace sprinkler heads and test the flow.
Watch for Weeping or Non-Stop Spraying
Right after your sprinklers are turned off, watch for a sprinkler head that "weeps" or seems to be overflowing with a slow stream of water. The valve that controls that zone is probably worn out and not sealing properly. You'll need to replace the valve.
If you have a sprinkler or sprinklers that stay on after you shut the system off, then that valve is probably jammed by a small rock or some other debris. You'll need to find that valve and flush it out so it will close and the water spray of your sprinklers will turn off properly.