How to inspect the sprinkler system
To inspect a sprinkler system, find the controller, backflow device and valves, then run each zone and watch it. Look for broken or tilted heads, leaks, and spray landing on pavement. Fix those, set a seasonal schedule, and ask your water utility if your backflow device needs testing. EPA suggests inspecting the system monthly.
What a sprinkler system inspection covers
A sprinkler system runs on a timer whether it works well or not, so problems can go on unseen for months. Experts cited by the EPA estimate up to 50% of residential outdoor water is wasted through overwatering. Homes with clock-timer irrigation use about 50% more water outdoors than homes without, and wasteful irrigation can lose up to 25,000 gallons and $280 over a six-month season.
EPA's WaterSense program breaks the check into four words, and they make a handy order of work.
- Inspect: broken or missing heads, and heads that are tilted or don't pop up fully
- Connect: leaks at joints, pressure regulators and valve boxes, and valves that don't close fully
- Direct: spray aimed at plants and lawn, not at driveways, sidewalks or walls
- Select: a controller and schedule that fit the weather
You'll also want to find the backflow preventer, the device that stops irrigation water from flowing back into your drinking water. Testing rules are local, so your water utility is the place to ask. Some require a certified test on a set schedule, and some don't.
How to inspect a sprinkler system, start to finish
- Find the parts
Locate the controller, backflow device and zone valves, and add them to your site sketch.
- Read the controller
Note the zones, start times and run times the last owner left. Take a photo before you change anything.
- Run each zone
Start them one at a time and walk the area, flagging any problem heads.
- Fix heads and aim
Clean or replace damaged heads, and re-aim any that spray hard surfaces.
- Check for leaks
Look at joints and valve boxes. Read the water meter with the system off.
- Set the schedule
Use the tuna can test. Avoid midday watering, and check your utility's allowed days and times.
- Call your water utility
Ask whether your backflow device needs testing, how often and who may do it.
How to read your sprinkler system inspection results
Stand in each zone while it runs, then walk it again after it shuts off.
| What you see | What it means | What to do |
|---|---|---|
| Head doesn't pop up, or barely sprays | Clogged or damaged head, or low flow | Clean or replace the head. |
| Geyser or a head that's gone | Broken head | Replace it. Don't run that zone until you do. |
| Soggy patch that stays wet between runs | Leak in the line or a valve not closing | Dig carefully after calling 811, or call an irrigator. |
| Water on pavement | Head out of line | Re-aim for head-to-head coverage on the planted area. |
| Runoff before the cycle ends | Water going on too fast | Use cycle-and-soak, with short breaks, especially on clay or slopes. |
| Dry brown patches | Gap in coverage | Check the heads around it before you add run time. |
| Meter moves with the system off | Possible leak | Close the irrigation supply valve and recheck. |
Leaks can be tiny and still be costly. An irrigation leak just 1/32 of an inch across can waste about 6,300 gallons a month, according to the EPA.
To set run times, use the EPA's tuna can trick. Put a few empty cans around a zone and time how long it takes to fill them with 1/2 inch of water. Run the zone that long twice a week, then adjust for the weather. Landscapes typically need about 1 inch a week including rain.
Fixing sprinkler heads, leaks and the backflow device
Heads and nozzles are simple swaps. Anything buried needs more care. Call 811 before digging, and keep in mind that private lines often aren't marked.
Leave the backflow device to a certified tester or licensed plumber. It protects your drinking water, and it's not a part to adjust by feel. If it's leaking, cracked or missing a part, shut off the irrigation supply and call.
An old clock-only controller is worth replacing. EPA says a WaterSense labeled controller, which adjusts to local weather and landscape conditions, can save an average home up to 15,000 gallons a year. Some water utilities offer rebates, so check before you buy. In freezing climates, ask your installer how the system should be drained for winter.
What homeowners say about sprinkler system leaks
On move-in day, check the sprinkler controller and turn it off until you're settled, so it doesn't soak movers and boxes. (Reddit)
How to inspect a sprinkler system: common questions
How often should I check my sprinkler system?
EPA suggests inspecting irrigation monthly. A full walk of each zone at the start of the season and a quick look during it will catch most broken heads and leaks.
Do I need to test my backflow preventer every year?
It depends on your water utility or local code, so call and ask. If testing is required, they'll usually tell you who is allowed to do it and how to file the result.
What time of day should sprinklers run?
Avoid the middle of the day, when the sun evaporates much of the water. Check with your water utility too, since many set their own watering days and times.
Sources: EPA
General guidance for U.S. homes, not professional advice. For gas, electrical and structural work, call a licensed pro.