7 Common Mistakes When Winterizing and Spring-Starting Sprinklers (And What To Do Instead)
By Turfrain
Homeowners most often make these mistakes when winterizing and spring-starting sprinklers: not fully blowing out lines, using too much air pressure, ignoring the backflow, shutting valves incorrectly, waiting too long for first freeze, skipping zone checks, and turning water on too fast in spring. Fixing these saves pipes, heads, and water bills.
What you’ll learn from this blog
The biggest winterizing mistake and how to avoid cracked pipes
Safe air pressure and timing for blowing out lines
Backflow prevention tips that protect your water and your wallet
When to shut down in fall and when to reopen in spring
A simple, step-by-step spring-start routine
How to spot small issues before they become soggy disasters
When it’s smarter (and cheaper) to call a pro
Start Here: The Blowout Everyone Rushes (And Regrets)
Summary: The most common and costliest mistake is an incomplete blowout or using the wrong air pressure. A few minutes saved in fall can mean a blown manifold in spring.
Details: Picture your irrigation lines like the lungs of your yard—if you don’t exhale fully before winter, ice expands and cracks things from the inside. Two things go wrong a lot:
Not enough volume: A tiny “pancake” compressor may puff air but can’t move water out of long runs.
Too much pressure: Cranking pressure can shatter fittings or atomize water into mist that refreezes.
What works better:
Use moderate pressure and adequate volume. For many residential systems, 50–60 PSI is safe for PVC zones; start lower (30–40 PSI) for drip or micro-spray. Check your system’s rating and never exceed it.
Cycle zones in short bursts. Run each zone for 1–2 minutes, rest 30–60 seconds, then repeat until only mist or air comes out.
Open low-point drains if you have them, and don’t forget lateral runs in the back corner of the yard—the ones we all swear we’ll remember later.
A quick story: I watched a neighbor blast 100 PSI through a small compressor to “get it done fast.” Spring arrived with a geyser by his mailbox. Ten minutes saved. Two sprinkler heads and a cracked elbow later… not so cheap.
The Backflow and Valve Trio People Forget
Summary: Skipping backflow prep, leaving valves half-closed, and ignoring little drains are classic slip-ups.
Details and fixes:
Backflow assembly care: Turn off the irrigation shut-off valve inside the house, then open the test cocks on the backflow preventer at a 45° angle to let trapped water drain. Insulate the assembly if it’s outdoors. Water trapped here is one of the first places to freeze.
Main valve position: Close the irrigation main fully. A half-closed valve can let water seep back into lines after you’ve blown them out.
Solenoids and manual bleeds: After blowout, pop each valve’s manual bleed briefly to burp any remaining water. It’s like tapping a straw to get the last drops out.
Timing Myths: First Frost vs. First Hard Freeze
Summary: Waiting for a “hard freeze” is the landscaping version of leaving for the airport at boarding time.
Details:
When to winterize: Do it before your first consistent overnight freeze (typically 32°F for several hours). Don’t gamble on forecasts; cold snaps aren’t polite.
When to spring-start: Wait until the risk of hard freeze has truly passed for your area—often after the last average frost date. If you must water early, hand-water or run the system midday on a mild day, then drain again.
Signs it’s time:
Fall: Leaves are mostly down, night temps dip into the low 30s more than once a week, and you feel that crisp bite after sunset.
Spring: Soil is thawed a few inches down, lawn growth restarts, and you’re not seeing frost on the car windows in the morning.
Spring Startup: Slow Is Smooth, Smooth Is Fast
Summary: The best spring-start feels boring—because nothing bursts.
A quick, no-drama, 5-minute-per-zone ritual:
Close all test cocks on the backflow and set valves to normal.
Crack the main irrigation valve open just a quarter turn. Let the system pressurize slowly for a minute.
Run the first zone and listen. Hissing that fades is normal; banging or sputtering forever is not.
Walk the zone: straighten tilted heads, clear soil around sprinklers, and look for “mystery puddles.”
Repeat for each zone, opening the main valve a bit more as you go, until fully open.
Pro tip: Replace at least a couple of tired nozzles each spring. New nozzles are like new eyeglasses—suddenly, coverage is crisp again.
Little Leaks, Big Bills: The Small Stuff That Sneaks Up
Summary: A few tiny issues drain money all season.
What to watch for:
Sunken or leaning heads: If the spray hits the sidewalk, you’re watering pedestrians, not turf. Shim or reset the body so it’s plumb and ½ inch above grade.
Clogged nozzles and filters: Sand and scale build up. A toothbrush and a rinse work wonders.
Invisible pipe breaks: A surprisingly lush patch or algae near a valve box can mean a slow leak.
Controller confusion: Old schedules overlap, leading to marathon watering. Start fresh: two to three days per week in spring, add time in heat waves, and always comply with local watering rules.
A friendly reality check: If the controller manual makes your eyes cross, you’re not alone. Snapping a picture and labeling zones on your phone is the best 60 seconds you’ll spend.
FAQ-style quick hits
How much air pressure to blow out sprinklers? Often 50–60 PSI for typical residential PVC zones and less for drip or micro. Use volume over pressure and always follow manufacturer specs.
Do I need to blow out if I have a “self-draining” system? Usually yes, or at least verify drains work and clear low spots. Trapped water hides.
When should I turn on my sprinkler system in spring? After the last likely hard freeze. If in doubt, wait a week; your lawn can handle it.
Can I use a small pancake compressor? For short zones, maybe, but expect multiple cycles. A higher CFM unit is safer and more effective.
Conclusion and a friendly nudge
Winterizing and spring-starting sprinklers doesn’t have to be stressful. Go slow, use the right pressure, pamper the backflow, and give each zone a quick walk-through. Your lawn will look better, and your system will last longer. If you want a second set of eyes—or just a hands-off, no-worries setup—Turfrain can help. Contact Us and we’ll get your irrigation dialed in for the season.
