How to Winterize Your Home Sprinkler System

Emily Fazio
·4 min read

Winterizing your outdoor sprinklers before the cold snap is important to help the system perform optimally and last a good, long time.

When temperatures drop, any residual water left in the system can freeze. This ice can damage pipes and valves. Winterization involves draining the water to safeguard your system from potential issues. Take care of it before the ground freezes, and rest easy knowing your watering equipment will be ready to efficiently irrigate when the warmer weather returns... without expensive repairs.

There are a few different drainage methods that will make it easier to prepare your irrigation for winter.

Before You Get Started

  • Inspect the entire system for leaks. If you find any, address them before winterizing to prevent further damage.

  • Consider hiring a professional sprinkler system service if you suspect damage. They have the expertise and equipment to help you check valves and internal components, identify issues, and plan so you can avoid costly repairs caused by cold-weather damage.

Three Methods:

The Manual Drain Method

In this method, manual drain valves are strategically placed at low points of the irrigation system. These valves are opened to allow gravity to drain water from the pipes and prevent freezing.

  1. Start by shutting off the main water valve to turn off the system. This valve is usually located in the basement, crawl space, or an underground valve box.

  2. Identify and open manual drain valves strategically placed at low points in the irrigation system. This allows gravity to facilitate the drainage of excess water from the pipes, minimizing the risk of freezing. There may be more than one drain valve, so consult your system's manual or contact the installer for guidance.

  3. Allow some time for the trapped water to drain. Be patient and let gravity do it's thing.

  4. Close the drain outlets. Once the manual drainage is complete, close the drain outlets to seal the system, protecting the drain hoses against wintertime ground temperatures.

The Automatic Drain Method

Consider yourself lucky if your system features automatic draining. It's a less complicated method that simplifies the draining process. Unlike manual valves, the auto drain valves are installed at low points in the irrigation system. These valves open automatically when the water pressure drops.

  1. Turn off the main water supply to the irrigation system.

  2. Open each zone. Activate each zone manually to relieve pressure and allow automatic drain valves to open.

  3. Allowed the water pipes to drain.

The Blow-Out Method

This draining method involves using an air hose to force water out of the irrigation system. It may be more work than automatic draining, but it's one of the most effective ways to ensure that all water is removed, even from backflow preventers, valves, and any exposed pipes. Follow your sprinkler system's manufacturer's guidelines to avoid damage.

Materials and Tools You'll Need

  • Air compressor with proper fittings and regulators

  • Pressure gauge to monitor air pressure

  • Quick-connect fittings

Step-by-Step Instructions For Blow-Out Draining

  1. Shut off the main water supply to the irrigation system.

  2. Identify the proper point to connect the air compressor. Use a quick coupler, like a quick-connect hose adapter.

  3. Set the pressure. Set the air compressor to the recommended pressure for your system (commonly 40-80 psi).

  4. Choose your starting point. With the blowout method, start with the zone farthest from the compressor and gradually work your way back. Open each zone's valve manually and allow the air compressor hose to blow out the water until only air comes out.

  5. Focus on the entire system. Pay special attention to mainlines, lateral lines, and any low points where water might accumulate. Let the air supply work through all of those areas.

  6. Repeat this process for each zone.

  7. Turn off the air compressor, disconnect it, and close all manual drain valves.

Tips for Insulating Your Irrigation System and Other Hoses

  • Insulate pipes and components. Wrap any valves above ground with insulation tape. Consider backflow device valves and water shut-off valves. This helps protect them from the extreme cold temperatures.

  • Winterize your garden hoses. Disconnect garden hoses from outdoor faucets and store them indoors. Place a hose bib over the faucet. Drain any residual water from the hoses before storing.

  • Use a backflow preventer. If you have a backflow device, it is essential to protect backflow valves from freezing.

  • Document your system. Take notes or create a map of your sprinkler system, including the location of valves, drains, and other key components. This will be useful for spring start-ups.