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How to Winterize Your Sprinkler System

Knowing how to winterize your sprinkler system is key to protecting the system’s pipes and valves from the cold. Learn about the steps you need to take in this guide.

Sprinklers save you a great deal of time and effort when it comes to creating and maintaining a lush, green lawn. However, that doesn’t mean that the sprinklers themselves don’t require their own maintenance. In most parts of the country, you ought to shut down your sprinkler system in the fall and bring it back online in the spring.

Particularly if you live in an area where ground temperatures dip below freezing, you’ll want to make sure that you’ve properly prepared the system for winter weather by draining out the water and insulating the sprinkler components. Here, we’ll go over how to winterize your sprinkler system in four easy steps.

Steps for Winterizing Your Sprinkler System

Some of these steps are easy to do on your own, but others require specialized machinery and the expertise of a professional. TruGreen, in addition to its lawn care services, offers sprinkler repair and maintenance to homeowners throughout the country.

If you’d like a free quote, fill out this quick form or call 1-866-817-2287 to speak to a customer service representative.

Step 1: Shut Off the Water

It will come as no surprise that the first step is turning off the water to the system with a main valve that’s usually found near your water meter. If your system has valves to prevent backflow, shut these off, too. There are usually two of these valves that lead into the backflow device; be sure to shut them both off. If your system doesn’t use potable water, it might not have a backflow preventer.

Step 2: Turn Off the Timer

If your system runs on an automatic timer, make sure you shut that off, too. Some systems have a “rain mode” that allows you to essentially power down the timer without losing any programmed information or settings. Allowing the system to run in rain mode throughout the winter is usually safe and shouldn’t run up your energy costs. In the spring, you can turn the rain mode off, and the timer should resume working normally.

Step 3: Drain the Water

It’s not enough just to keep water from flowing into the system; you also need to drain out the water that’s already in there. This is the biggest and most time-consuming step in the process, but it’s absolutely vital. There are three main methods of drainage depending on what type of sprinkler system you have.

  • Manual Draining: Some sprinkler systems may allow you to drain the water manually. These systems have shut-off valves at low points or ends of the piping. Make sure to wear eye protection while completing this step because the water supply in the system is under pressure. Slowly open the valves one at a time and let the water run out, then close them when finished.
  • Automatic Draining: Other systems have components that will automatically drain the water once the main valve is shut off and the water pressure drops. You can usually activate the system by running one of the sprinkler heads with the water supply off. However, there will still be some water trapped within the valves themselves. Locate the solenoid on each valve—a plastic cap with wires coming out of the top—and loosen it. This will allow air to flow into the system and water to flow out.
  • Blow-Out Draining: Some sprinkler systems allow you to hook an air compressor up to the pipes to force the remaining water out of the sprinkler heads. However, this method is destructive and even dangerous when tried on a sprinkler system that isn’t built for it. Additionally, it’s worth mentioning that a typical DIYer’s air compressor might create the 50 PSI (pounds per square inch) of pressure needed to clear out PVC piping. However, at-home machines can’t usually generate the 10 CFM (cubic feet per minute) of volume needed to quickly and completely blow out the water. For these reasons, we don’t recommend attempting the blow-out draining method on your own. Even if you don’t damage the system, you might not get the job done completely, and even a little water left in a sprinkler system over the winter can cause problems. Hiring a professional for this job is a once-a-year cost that’s well worth it.

Step 4: Insulate Above-Ground Components

Finally, make sure that all the above-ground parts of the sprinkler system are properly insulated from the weather. The main shut-off valve, plus any exposed pipes or backflow preventers, should be wrapped in foam covers or insulation tape. On the backflow preventers, make sure not to block any air vents or drain outlets.

Double-Check the User Manual

Particularly if you’re winterizing your sprinkler system for the first time, make sure you double-check the manufacturer’s user manual. The steps presented here are generic to most systems, but you want to see whether you need to take any specific actions for your sprinklers.

Lawn Care Help

If you don’t feel comfortable winterizing your sprinkler system on your own, there are plenty of professional lawn and sprinkler care services standing by ready to help each fall. We recommend the nationwide provider TruGreen.

For a free quote for TruGreen’s lawn irrigation services, including the Annual Sprinkler Maintenance Plan, call 1-866-817-2287 or fill out this online form.

Our Rating Methodology

The This Old House Reviews Team backs up our lawn recommendations with a detailed rating methodology that we use to objectively score each provider. We review lawn care plans and packages, navigate the provider website and speak with customer service representatives, request quotes, and analyze customer reviews for each provider. We then score the provider against our review standards for plan options, additional benefits and customizability, availability, trustworthiness, and customer service to arrive at a final score out of 100.

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