How to Winterize Your Sprinkler System

Prepare Your Irrigation System When the Forecast Call for Freezing

Winter is approaching, and sprinkler winterizing should be right behind! If you own an irrigation system, it needs to be taken care of before there’s cold weather. It’s not a fun homeowner experience, but it’s less painful than fixing things at a later date.

What do you get if you don’t? Frozen pipes, burst valves, and busted sprinkler heads. And you won’t even notice damage exists until spring when you turn power back on to everything.

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

Why Is Winterizing a Sprinkler System Worthwhile? 

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

Ignore the need to winterize and pipes usually are the first to fail. They crack and break up. Plastic valves crack and sprinkler heads get pushed entirely out of where they should be due to ice building up inside.

Here’s something to keep in mind regarding different systems. The majority of the newer units employ either rigid white PVC pipe or flexible black polyethylene. PVC is brittle, so it may freeze and crack with little resistance. Polyethylene is better able to tolerate the cold because it flexes, but even that will burst if water somehow gets left inside and then expands.

What’s the Best Time to Winterize Sprinklers? 

The most important part of winterization is that you do it before temperatures drop below freezing. Since that happens at different times in different places, precise timing really depends on exactly where you live.

Down south, it might be late November or early December. Honestly though, some southern areas may not need it at all. Most Andy’s Sprinkler, Drainage & Lighting locations are in southern and coastal areas, but we do offer additional winterization services in areas where sustained freezes are more likely.

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

The optimal time is right before the first freeze arrives. But if a sudden cold snap shows up? Simply shut your system off at the controller and reach out to us ASAP. We’ll make sure everything’s taken care of for the remainder of the season.

3 Main Methods to Winterize a Sprinkler System 

Automatic Drain Method 

If your system has this setup, it does half the work for you. Automatic drain valves open and drain water whenever pressure drops below a certain level.

However, this is where things get somewhat tricky. Those valves work great for the sprinkler heads and the lateral pipes, but they won’t do anything to the main supply line. You still have to drain that mainline by hand, or you’re asking for a major break. You should also check any check valves that you might have, as these will also hold water.

The best part about this winterizing solution? It takes virtually no effort on your end. The worst part? It’s not foolproof. You might still wish to do a partial blowout as a safeguard.

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

Manual Drain Method 

This is a really hands-on one. Start by shutting off the main water supply to your irrigation system. Sounds easy, but people skip this step all the time. It doesn’t qualify to turn off a hose spigot. You need to find the actual main shut-off valve, which is usually hiding somewhere in your basement or utility room.

Then open all of your manual drain valves at the low points in your system. Proceed to your controller and run one complete cycle with the water already off. This cycle opens all of the automatic valves and drains any pressure being held in the mainline. Once that cycle is finished, switch your controller to the off or rain mode setting.

The advantage of this method? It won’t break the bank. The disadvantage? Water likes to hang around in low spots or tough areas to reach, and you might miss some.

Do it yourself? Yes, if your system has manual drain valves and you don’t mind finding them and getting them open.

Blowout Method 

This process uses a big air compressor that shoots compressed air through your pipes to force all of the water out. This is a great method, regardless of which climate you live in or what kind of system you have.

The issue is, you need specialty equipment that gets to the right PSI (pounds per square inch) and CFM (cubic feet per minute). Generally, you’re looking at 40 to 80 PSI and a compressor that provides 30 to 100 CFM. Crank the pressure too high and you can damage your pipes or blow them entirely apart. Go too low and water gets left behind.

You need specialized gear for this kind of task, 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 cold snaps and other unexpected weather surprises.

A Handful of Extra Winterization Tips 

• 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!
• 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.

Simplified Steps For a Sprinkler Blowout 

Really want to do a blowout yourself? Be careful as you follow this quick how-to. 

• Start off by shutting the water supply to your irrigation system and killing the power to the controller.
• Then you need to vent the pressure in the system. Open one sprinkler head on whichever zone is farthest from your compressor.
• Hook up the air compressor to your system’s blowout port. Make sure you have the proper adapter for this.
• Begin in the area either furthest from the compressor or the highest on the elevation scale.
• Now this is where things get interesting. Add the air slowly. Slowly open that compressor valve. Don’t go over 80 PSI if you have PVC pipes (50 PSI for polyethylene). This is very important!
• Monitor your sprinkler heads carefully. At first, you’ll have a heavy spray of water shooting out. Let it run until you can only see a thin clear mist of air.
• Work through all your zones separately and do it all over again.
• When you get to the final zone, leave one sprinkler head open while closing off the compressor and the valve. This releases any residual air pressure.
• Unhook the compressor and make certain all your system valves are shut.

Consider operating each zone twice. That way you can be sure you actually drained out all the water.

DIY vs. Hiring a Pro 

If you want to tackle this job yourself, be certain you realize 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.

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. 

Typical Mistakes Made When Winterizing

• 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.

Sprinkler System Winterization FAQs

Can I run my sprinkler system in winter?

Yes, we highly recommend doing so. You will need to adjust watering schedules for winter. Watering as long as you can into winter will help your lawn stay gorgeous until spring. 

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 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.

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.

Let the Winterizing Begin (When the Timing Is Right)

A sprinkler system winterization isn’t difficult, especially when you trust Andy’s. It safeguards your grass and prevents some of those annoying, costly repairs down the line. 

When you see colder weather approaching, reach out to Andy’s to schedule your sprinkler system winterization! Here’s what our customers love about us:

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