Many homebuyers know to thoroughly inspect a home's foundation, electrical system and plumbing before agreeing to buy a house. But experts say it's important to check out what's outside a home's walls as well.

For instance, taking a few steps to inspect a property's sprinkler system could keep you from waking up to a problem down the road. Old sprinkler systems or systems in ill repair are vulnerable to a variety of problems-from leaks to blockage. These problems can harm the health of your lawn and even cause serious damage to your yard and landscaping. To help homeowners avoid buying someone else's outdoor irrigation issue, Dave Johnson, an irrigation expert at Rain Bird, offers these tips:

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.

After the system has been turned on for a few minutes, stroll around the 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.

Open and close each individual valve, checking for moisture caused by cracks or broken seals in the pipes or exterior casing. Most valves contain a screw or knob on top that can be easily turned by hand.

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.

If the system is connected to a rain sensor, test the sensor by first turning on one of the zones, and then giving the rain sensor a good soaking with a garden hose. If the irrigation system does not stop, there may be a problem.

Ask the sellers if they have a maintenance record, or a receipt from the last time they had the system winterized by a professional.

If you are not comfortable conducting an inspection of the sprinkler system yourself, find an area landscape professional to do a routine inspection.