How to Winterize (or Blow Out) Your Sprinkler System

Get Your Irrigation System Prepped for Freezing Temps

Winter’s on its way, and sprinkler winterization should be, too! If you have an irrigation system, it needs attention before low temperatures arrive. It’s not a fun homeowner chore, but it’s better than facing expensive repairs later. 

 

Know what happens if you skip this? You’re risking frozen pipes, cracked valves, and split sprinkler heads. Plus, you won’t know there’s damage until spring when you turn everything back on.

 

Ready to winterize your sprinkler system? We’re sharing when to winterize, the different ways to do it, and so much more!

What Does Winterizing a Sprinkler System Mean? 

In short, winterizing is about getting all the water out. Every last drop. The whole point is leaving your pipes, valves, and sprinkler heads dry, so there’s nothing left for freezing temps to wreck.

 

When people ignore this, the pipes are usually what go first. They crack and split apart. Plastic valves shatter, and sprinkler heads get pushed right out of where they’re supposed to sit because of the ice building up inside.

 

Here’s something to keep in mind about different systems. Most newer ones use either rigid white PVC pipe or flexible black polyethylene. PVC is pretty brittle, so it cracks without much fight when it freezes. Polyethylene can take the cold better since it bends, but even that will rupture if water gets left inside and starts expanding. 

When Should You Winterize Your Sprinklers? 

The biggest thing is that you get it done before temperatures drop below freezing. Of course, exact timing depends on where you live.

 

Up north, you’re usually looking at late September through early November. If you’re in the mountains or anywhere with high altitude, you’ll need to winterize the sprinkler system even earlier.

 

Down south, it might be late November or early December. However, some southern regions may not need it at all. Reach out to our partners at Andy’s Sprinkler, Drainage & Lighting or Rainscapes (if you live in Knoxville, TN) to learn more. While most of our partner locations are in southern and coastal areas, they provide additional winterization services in areas where sustained freezes are more likely.

 

Again, don’t wait until the last minute! Everyone tries to schedule this at the same time, so booking ahead saves you the headache. 

 

The sweet spot is right before that first freeze hits. If a surprise cold snap sneaks up, just shut your system off at the controller and reach out to us. We’ll make sure everything’s taken care of for the rest of winter.

3 Main Methods to Winterize a Sprinkler System 

Manual Drain Method 

This one’s really hands-on. Start by shutting off the main water supply to your irrigation system. Sounds basic, but people forget this step all the time. Turning off a hose spigot doesn’t count. You need to find the actual main shut-off valve, which is usually tucked away in your basement or utility room somewhere.

 

After that, open up all the manual drain valves at the low points in your system. Then head to your controller and run one complete cycle with the water already off. This opens up all the automatic valves and gets rid of any pressure stuck in the mainline. Once that cycle finishes, switch your controller to the off position or rain mode.

 

The best part about this method? It won’t cost you much. The downside? Water loves to hide in low spots or tricky zones, and you might miss some.

 

Can you do it yourself? Sure, as long as your system has manual drain valves and you feel confident finding them and getting them open.

Automatic Drain Method 

If your system has this setup, it handles part of the job for you. These automatic drain valves kick in and release water whenever the pressure drops below a certain level.

 

But here’s where it gets tricky. Those valves work great for the lateral pipes and sprinkler heads, but they won’t touch the main supply line. You’ve still got to drain that mainline yourself, or you’re asking for a major break. Also, it’s worth checking any check valves you have, since they can trap water too.

 

The best part about this winterizing option? It barely takes any work on your end. The catch? It’s not foolproof. You might still need to do a partial blowout just to be safe.

 

Can you do it yourself? Mostly. But you need to know what your system can and can’t handle.

Blowout Method 

This process includes a big air compressor that shoots compressed air through your pipes to force every bit of water out. It works really well, no matter what climate you’re in or what kind of system you have.

 

The thing is, you need specific equipment that hits the right PSI (pounds per square inch) and CFM (cubic feet per minute). Usually, you’re looking at 40 to 80 PSI and a compressor pushing 30 to 100 CFM. Crank the pressure too high and you can damage your pipes or blow them apart completely. Go too low and water stays behind.

 

Nothing gets your system more thoroughly dry. However, you need specialized gear, and there’s real risk involved if you don’t know what you’re doing.

 

But do you need a blowout for your irrigation system? Only if you’re located in a region with long-lasting freezes. However, most of our customers live in warmer climates that don’t need blowout services.

 

Other options for winterization? Temporary removal or insulation of aboveground irrigation components. This safeguards your system from surprise cold snaps and other unexpected weather events. 

Step-by-Step Guide to a Sprinkler Blowout 

If you’re dead set on doing a blowout yourself, here’s how. Just be extremely careful.

 

• Start by shutting off the water supply to your irrigation system and killing the power to the controller.
• Next, you need to relieve the pressure in the system. Open up one sprinkler head on whichever zone is farthest from your compressor.
• Hook the air compressor up to the blowout port on your system. Make sure you’re using the right adapter for this.
• Begin with the zone that’s either farthest away from the compressor or sitting at the highest elevation.
• Now comes the important part. Introduce air slowly. Open that compressor valve nice and easy. Don’t go over 80 PSI if you have PVC pipes (50 PSI for polyethylene). This matters a lot!
• Keep your eyes on the sprinkler heads. At first, you’ll see a heavy spray of water coming out. Let it keep running until all you’re seeing is a thin, clear mist of air.
• Move through all your zones one at a time and repeat everything.
• When you get to the final zone, leave one sprinkler head open while you shut the compressor down and close the valve. This gets rid of whatever air pressure is still hanging around.
• Disconnect the compressor and make sure all the valves on your system are closed.

 

Consider going through each zone twice. That way, you know you actually got all the water out.

DIY vs. Hiring a Pro 

Hiring a professional has some real advantages when it comes to winterizing a sprinkler system. 

 

• The job gets done more quickly and efficiently. 
• Everything is done safely. Even better, you’re not standing there second-guessing yourself the whole time.
• You’re more likely to avoid costly, surprise repairs. An irrigation expert makes sure everything’s actually empty and protected, which means you’re not firing up your system in April only to discover cracked pipes and busted valves. 

 

If you want to tackle this yourself, just know what you’re getting into. 

 

• The biggest risk of a DIY blowout is filling your pipes with too much pressure. It’s easier to do than you think. Plus, if those pipes are damaged, you’re looking at the exact repairs you were trying to avoid in the first place.
• There’s also the chance you don’t get all the water out. Maybe you missed a low spot, or a zone didn’t drain completely. You won’t know until it freezes and causes problems.
• Also, some system warranties get voided if you don’t have professional maintenance done. It’s worth checking before you grab your tools because saving a hundred bucks now isn’t worth losing coverage on a sprinkler system that costs thousands.

Additional Winterization Tips 

• Insulate exposed elements. Grab some foam insulation covers and wrap up your backflow preventer and any piping that’s sitting above ground. 
• Shut your controller down. Either flip it off completely or put it in rain mode. Don’t just yank the plug out. If there’s a backup battery in there, leave it. It actually helps protect the unit from condensation building up inside.
• Deal with your hoses. Unhook all your garden hoses, make sure they’re totally drained, and bring them inside. Then put some insulated covers on your outdoor faucets.
• Look into a smart controller. Some of the newer Wi-Fi controllers have rain sensors and freeze alerts built in, so they can stop the system from running automatically when it gets too cold. This protects your grass, roots, and sprinkler system from serious damage!

Common Winterizing Mistakes to Avoid 

• Forgetting a zone. It only takes one zone with water sitting in it to turn into a huge mess.
• Using the wrong compressor. That little compressor you’ve got in the garage won’t cut it. You need something more powerful for proper sprinkler winterization.
• Ignoring the backflow preventer. It costs a lot to replace, and it needs its own attention. You’ve got to drain it and insulate it separately from everything else.
• Waiting too long. Don’t sit around until you hear the first freeze warning on the news. By that point, every irrigation company in town is getting slammed with calls, so you’ll be stuck waiting.
• Not double-checking. Always take another look at the low points and valves to make sure water isn’t pooling anywhere. It’s worth the extra few minutes.
• Small details that cause big problems. Our irrigation partners can identify leaks and damage before winter weather. They also monitor spray patterns, ensuring water isn’t landing on concrete or hardscapes, which can lead to ice and potential hazards.

 

FAQs About Sprinkler Winterization 

How long does a sprinkler blowout take?

A professional blowout for a typical residential sprinkler system takes around 30 minutes, but a DIY blowout would probably take an hour or more.

 

Can I not winterize if I live in a warm climate?

If your winter temperatures rarely hit freezing, you can probably get away with just shutting off the system. But if you see temperatures below 32 degrees Fahrenheit in the forecast, it’s better to be safe.

 

What PSI is best for a blowout?

Don’t exceed 80 PSI. For flexible poly pipe, stay at 50 PSI or lower to avoid damage.

 

What if I forget to winterize my sprinkler system?

Shut off the water to the system and set the controller to “rain mode” immediately. Then call a professional ASAP to drain it. This isn’t ideal, but it’s better than nothing.

 

How do I know if it’s fully drained?

During a blowout, you know a zone is done when the sprinkler heads are emitting a fine, clear mist instead of a wet spray.

 

Can I run my sprinkler system in winter?

Absolutely! Simply adjust watering schedules for winter. Continued watering helps your lawn stay resilient until spring. 

Now’s the Time to Winterize!

Winterizing your sprinkler system isn’t complicated, but you shouldn’t skip it. It protects what you’ve put into your lawn and keeps you from dealing with frustrating, expensive repairs later on.

 

That’s why we teamed up with Andy’s Sprinkler, Drainage, and Lighting as well as Rainscapes (in Knoxville, TN). Here’s what their customers love about them:

 

• Certified, experienced technicians
• Systems tailored to your specific yard
• High-quality, long-lasting materials
• Stress-free experience

 

Depending on your location, reach out to Andy’s or Rainscapes today to schedule your sprinkler system winterization as soon as possible!