A well-maintained lawn and garden can increase the value of your property, and a well-maintained irrigation system is the way to achieve healthy plants. In addition, a properly running system is more efficient, which results in less wasted water. Whether you do the irrigation inspection yourself, or pay a professional to do it, the time and/or money uncovering any potential problems will be well spent.
Find and check the automatic sprinkler timer and make sure it is plugged into an unobstructed and visibly safe power supply in a weather-safe environment. An improperly placed electrical timer box is more susceptible to an electrical short, which can wreak havoc on an automatic irrigation system.
Test the timer to make sure that each individual sprinkler zone can be turned on manually from the timer itself. Failure of zones to turn on may indicate that the timer is improperly wired, or needs replacing. Most timers are easily turned on using the "RUN STATIONS MANUALLY" option located on the face of the controller.
After the system has been turned on for a few minutes, walk around the house and yard to check for any moisture in unusual spots, exposed pipes that may be prone to cracking, major brown spots around sprinkler heads, saturated turf or soil, sick and diseased plants. Each may be an indication of improper watering caused by a faulty irrigation system.
The sprinkler system valves are often located outside where the water supply exits the house, and are usually grouped together in a single location. Open and close each individual valve manually, checking for any moisture caused by cracks or broken seals in the pipes or valve's exterior casing. Most valves contain a screw or knob on top that can be easily turned by hand.
Using the valves or timer, turn on each watering zone and check each sprinkler head. Any head that does not pop up, or otherwise operates improperly may need to be replaced. It is also possible that a sprinkler head that does not pop-up is a sign of a problem with the water pressure, and may indicate that there is a leak in the system somewhere. Let the system run for 3 minutes and then check the area to see if there are any extremely soggy spots or rising "blisters" that may be caused by a cracked pipe underneath the soil.
If the system is connected to a rain sensor, make sure it is connected to the timer and located in a place on the property that is free of obstructions so that watering does not occur when it is raining. You can test the rain sensor by first turning on one of the zones, then give the rain sensor a good soaking with a garden hose. If the irrigation system does not stop, there may be a problem.
In climates that are prone to freezing temperatures, prospective homebuyers should inquire with the seller regarding the winterization of the irrigation system each fall. By asking the seller if they have a maintenance record, or a receipt from the last time they had the system winterized by a professional, buyers can be assured that the system has been prepared for the onset of freezing temperatures, decreasing the chances of cracked pipes or other problems caused by below freezing temperatures.
If you are not comfortable conducting an inspection of the sprinkler system yourself, then find a local landscape professional to do a routine inspection.