Prevent freeze damage by gravity draining your sprinkler system!

Prevent freeze damage by gravity draining your sprinkler system!

Fall in Colorado means rapid temperature swings, sometimes unexpectedly. Often times the days are warm & sunny while the nights dip to below-freezing temperatures. Sprinkler winterization is a must in Colorado to prevent costly damage to your system due to freezing temperatures. On average the first hard freeze occurs during the first week of October in Denver. One of the most common questions we get asked this time of year is “what can I do to protect my sprinkler system during a freeze if it hasn’t been winterized?”.

Perhaps a freeze came on unexpectedly and you’re not able to schedule a winterization in time, or perhaps freezing temperatures are only forecast for a few nights with much more warm weather in the future. The instructions below will outline a quick process for gravity draining your system before a freeze to prevent damage. Please note that this process is effective for short stints of freezing temperatures but your system will still need to be fully winterized prior to prolonged freezing winter weather. 

Please note:

If an ACA customer chooses to gravity drain their system, an ACA team member MUST confirm that it was drained correctly for our Freeze Free Warranty to be valid. Our technician must enter the home to check the turn-off valve to complete the winterization process.

We cannot offer a warranty to systems that do not receive an in-home inspection, or an onsite inspection if the valve is outside the home.

The first system component to be damaged in a freeze is most often the backflow prevention device. By gravity-draining this device you can protect your system and help to ensure that it and the rest of your system can be winterized at a later date without any freezing or blockage.

Please follow these steps prior to the freeze…

  1. Locate and turn the sprinkler shutoff valve in basement/crawlspace to the off position (see photo below). Please note, homes in Commerce City/ Henderson typically do not have an interior shutoff but instead it is located near the water meter and curb under a small round metal lid. This is called a curb stop and may require a sprinkler key to turn off. 

  1. Find the backflow preventer (vacuum breaker) located on the side of the house (pictured below). Turn the handles and all screw ports 45 degrees and leave that way (represented by the black lines below).

  1. Return to the shutoff valve and locate the small drain (bleeder cap) near the valve. Place a bucket below the drain to catch water that will gravity drain to this point. Unscrew the small cap from the drain and place somewhere safe. Most water should drain within 5-10 minutes of opening this drain however, you may notice a small drip for up to 12 hours. Leave the drain cap off and check periodically to be sure that water is not continuing to drip after 12 hours. If water does continue to drip, this could indicate a failing shutoff valve and a plumber will need to be called to replace that valve.
  1. Many customers choose to wrap the backflow prevention device with towels, blankets or insulation. If you choose to do so, please BE SURE TO COVER THESE WRAPS WITH SOMETHING WATERPROOF (a thick trash bag or two will do the trick).
  1. Schedule your winterization appointment prior to prolonged freezing temperatures by visiting 

We hope that this helps prepare you for unexpected cold weather! If you have further questions regarding winterization, please visit