How to Blow Out Your Sprinklers Before Winter Sets In
Blowing out your sprinklers is the act of winterizing your outdoor or garden irrigation system. This involves turning off the main source of water, explains Brandon Haley, CGM, a landscape expert and grounds manager, and is considered an extremely important task—especially since homeowners want to avoid costly damage caused by frozen or burst pipes. Ahead, exactly how to blow out your sprinklers before the chill sets in.
Use an air compressor.
To blow out an irrigation system, air is forced into the pipes via an air compressor, notes Haley. "Commercial companies utilize large air compressors that generate a lot of volume, but a homeowner can use a portable option for their residential system if they want to tackle the job," he explains. "Just be prepared for it to take substantially longer for the volume and pressure to build in the lines to force the water out." If this is your first time wrangling this outdoor project, start by finding your connection point, which should be near your sprinkler system's water source. This, says, Haley, is where you should hook up the air hose. "Another way to remove water from the irrigation lines is to design the system so water flows or drains to the lowest part of the yard—and put a relief valve at the end of the line," he adds. "Unfortunately, if your system is already in the ground without this feature, you will have to use compressed air."
Never skip this task.
As colder air moves in, the risk of frozen or broken pipes increases. "In areas of the country where the freeze line is below your irrigation piping, pipes could freeze if you do not blow out the system," Haley says. "Water expands when it freezes, so every component of your irrigation system is susceptible to cracking or breaking." This holds true even in locales where pipe freezing is rare, since it's possible for your irrigation heads to ice over. "Irrigation heads are not insulated, so prolonged cold temperatures are a risk to anyone," Haley says, noting that homeowners should take action before there's a problem.
Time it right.
Tackle your sprinkler blow out before the first freeze of the year. "Make sure to either take time to do this yourself or schedule a contractor well in advance," Haley says. "Contractors become very busy during the fall, so make sure to call around Labor Day to set up your appointment." While the process doesn't take long, give yourself a few buffer days before that first expected hard-freeze, he adds.
Learn from the professionals.
If you're handling this task solo, be patient and take your time. "Make sure that each zone is fully blown out. Water and air will come out of the last sprinkler in the line," he says, adding that you should give each zone plenty of time to fully release. "Turn each zone on from the controller until you have completed your whole system." Then, when spring comes, allow your system to start back up gradually. "At this time, open the water supply valve to just slightly more than a trickle and allow plenty of time for the system to fill with water," he says. "Once the system fills, increase the water to about 50 percent capacity and open the zones one at a time." You should do this until all of the air is out of the network. "If you open the system before all the air is let out, you will cause water hammer, otherwise known as 'hammer head.' This will break irrigation pipes and heads."