Do you live in a cold region of the United States? Do you know how to winterize your garden sprinkler system for the annual freeze? Whether winterizing the sprinkler system or repairing damaged components, you’ll need to drain it. Keep reading to learn more about the draining method professional lawn sprinkler companies use to drain sprinkler systems.

How To Drain Sprinkler System

You have several options for draining the sprinkler system, depending on the type of drain fitted by the installation team. Before draining, inspect the system and determine the types of drain valves. If you don’t know, contact a local sprinkler system company to find out which type of drain valve you have.

Typically, you’ll have a manual or automatic drain valve. However, some irrigation systems may require blowing out to drain them.

Shut the Water Valve

Start with turning off the water supply to the system by turning off the main valve. You’ll find the water valve close to the water meter. If the irrigation system has backflow prevention valves, you’ll also need to shut it off. Make sure to check the water pressure in the system.

Turn Off the Timer

If your irrigation system has an automated timer, set it to rain mode before draining. If you don’t have rain mode available, turn it off.

Manual Drain Valve

You’ll find the manual drain valves downstream of the zone valves at the lowest points in the system, where the water collects after shutting off the sprinklers. Close the primary valve to the irrigation system. You’ll find it on a separate “T” connection near the water meter.

Open the manual drain valves in each zone to allow the water to drain completely from the sprinkler heads and pipes. For best results, leave the valves open for two or three days.

You’ll open the valves upstream of each zone to drain water from the primary irrigation line. Run one of the sprinkler heads to drain any remaining water in the system. Ensure you actively monitor the remaining water and adjust the drainage time according to the current temperature in degrees Fahrenheit to guarantee the complete removal of all water.

Automatic Drain Valves

The pressure falls after closing the supply valve, and the water drains automatically. Open the irrigation drain cap between the backflow device and the main valve. This action eliminates any remaining water trapped in the pipes. Lift the sprinkler heads and drain any residual water.

Blowout Draining

The blowout draining method is for professionals. Do not try to DIY the blowout draining method unless you have experience installing and maintaining irrigation systems. A professional landscaper will use an air compressor to force compressed air into the system to blow out the remaining water.

If done incorrectly, this method can damage the equipment, and you might hurt yourself. Consult the manual before attempting any blowout. Many systems can’t handle high-pressure purging. Call a professional irrigation service in your area to address the problem for the best results and a service guarantee.

The Final Step in Winterizing Your Sprinkler System

If you’re winterizing the system, insulate the components after draining. Cover exposed pipes, sprinkler heads, backflow preventers, and shut-off valves with insulation tape or foam.

Ensure you don’t block drains or vents on the backflow preventers. With proper drainage and insulation, you won’t experience any damage to the system when the cold weather arrives. Also, ensure to drain the excess water and adjust the air pressure accordingly.


Why is it necessary to drain my sprinkler system?

Draining your sprinkler system is crucial, especially before winter or periods of prolonged non-use, to prevent water from freezing and causing damage to pipes, valves, and other components. Frozen water can expand and crack pipes, leading to costly repairs.

When is the best time to drain my irrigation system?

Ideally, you should drain your sprinkler system before the onset of freezing temperatures. In colder climates, this is typically done in late fall, while in milder climates, it can be done in early winter. Additionally, if you anticipate an extended period of non-use, such as during a drought or vacation, it’s advisable to drain the system then as well.

Pioneer Underground Lawn Sprinklers | Omaha’s Best Commercial & Residential Sprinkler Systems

Contact Pioneer Underground Lawn Sprinklers to schedule a free estimate on a system install or to find out what you can do to make your existing system more efficient. We welcome commercial and residential clients. And remember, whether you need our services now… or later in the season, Your Healthy Lawn is Our Passion and we are only a phone call away! Call 402-934-7900 to schedule your service.