Bio Green Outdoor Services, LLC Lawn Care & Sprinkler Learning Center (703) 450-0034

Sprinkler systems are valuable and complex hydraulic machines permanently buried underground in your yard, so it is important to protect your investment with periodic maintenance and seasonal adjustments. As with any plumbing fixture, there is risk of damage associated with freezing conditions, so it is vital that you turn your sprinkler system off at the beginning of winter and turn it back on in the spring. In addition, you should consider having your irrigation professional “winterize” your system to protect sensitive components, like your backflow preventer.

“Winterizing” and Winter “Blow Outs”

Having your irrigation system professionally “winterized” or “blown out” is a good idea because it can save you from damaging winter freezes and the costly repairs that follow. Blowing out your sprinkler system involves the use of compressed air to force any remaining water out of your irrigation system once the water source is shut off. This way, no water is left in your irrigation system’s plumbing and it cannot freeze, which could cause pipes to burst.

What To Do When There is a Risk of Freezing

Having your system winterized and checked by your irrigation professional is a good idea–it’s a small investment that can save you lots of money in repair costs and the annoyance of having a broken sprinkler system. Some irrigation professionals (like Bio Green) offer guarantees on winterization services that can protect your system from damage for that season. If your irrigation professional uninstalls your backflow preventer and leaves it in your care, it is important that you keep it in a location where it will not be damaged by freezing temperatures until the spring.

If your system is active and unexpected freezing temperatures are imminent, you must protect your sprinkler system.
First, turn off the water supply to your sprinklers. Then, using the controller or your mobile device application, run every zone in manual mode. This will partially remove water from the system and introduce air space into the piping. After each zone has run, turn your controller off. Lastly, wrap your above ground backflow preventer in a blanket to protect it from freeze and wind chill.

Turning Your System on in the Spring

Your irrigation professional likely offers a Spring turn-on service. To get back to watering your lawn as you normally would, set up a turn-on appointment with them. Depending on the design of your system, you may have to adjust valves prior to service.

During your turn-on appointment, the technician will:

  1. Verify the backflow preventer is installed and closed off.
  2. Verify all valves in the system are closed.
  3. Verify the drain/blow out point is tight.
  4. Locate the main water shut-off for the irrigation system.
  5. Verify the drain valve is closed.
  6. Slowly turn the main irrigation supply line on.
  7. Verify water is not leaking anywhere in the system.
  8. Pressurize the backflow device and charge the irrigation main line.
  9. Verify there are no leaks again.
  10. Fully open the backflow device.
  11. Manually turn each zone on and verify each sprinkler head is working properly.
  12. Return the system controller to auto mode.

Additional steps may be involved for systems with pumps.

Spring Turn-on Preparation – If You Have a Basement Tie-In

Be sure to close the outside ball valve. Refer to the picture below for a more detailed look at preparing your system for a turn-on service:

Spring turn on instructions

After closing the outside valves (located outside of your house) as shown in above photograph, turn on inside water supply in basement, slowly. You should hear the sound of water running briefly and then stop. If water continues to run, check ball valves outside to be sure they are properly closed.

If your backflow device was uninstalled from your system for winter storage, be sure to have it ready for the irrigation technician that comes to service your system for turn-on so that he or she may reinstall it.

Bio Green is happy to help with spring turn-on and winterization services for your irrigation system. Call our office in Sterling, Virginia at (703) 450-0034 or visit our website at

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