How to Winterize an Irrigation System

If you have an irrigation system for your garden, you’ll need to make sure you properly winterize it to prevent breakage on your sprinklers or even worse, a busted and leaking pipe. Keeping your sprinkler system maintained and healthy is the best way to keep it lasting as long as possible. There are a few different methods you can use to prepare your sprinkler system for the freezing months and keep your irrigation system installation intact so let’s have a look at a few of them.

Draining your system for the winter

Step one will be draining or blowing out all of the water that’s sitting in your sprinkler systems pipes. You can do this yourself if you are familiar with the sprinkler lines and drainage or you can contact a professional to help you. The type of draining you’ll need to do will heavily depend on the type of sprinkler system you have installed. If you have someone you’ve used for your irrigation system installation, they will be able to let you know the type of system you have.

Manual Drain

For systems that are equipped with a manual drain, it’s as easy as opening a valve. First, you’ll need to turn the sprinkler system off so no water is currently running through it. After you’ve done that, look for the manual they will be located at the ends and the low points of the system. Open all the valves and let the water drain out completely, then make sure you’ve drained your backflow device.

If your irrigation system has sprinklers with check valves that raise up, make sure you raise them and let them drain out completely too. This will make sure your sprinklers don’t get damaged from frozen water.

Automatic Drain

Some systems will come with an automatic draining system that drains the water once the water pressure falls below a specific number of pounds per square inch. To drain a system with automatic drain, turn the water off and briefly run one of the sprinkler heads to drain off the water and reduce the pressure. This will trigger the automatic drain and the rest of the pipes will clear themselves out but you should also check on the water between your shut-off valve and backflow device to make sure that thas drained too.

These types of systems can also come with raising sprinkler heads so make sure to raise the sprinklers and clear out the check valves.

Blow Out System

The blowout system involves using compressed air to blow all of the water out of the sprinkler heads and leave your pipes as dry as possible for the next year. This can only be done on certain sprinkler systems that are strong enough to handle the air pressure so be careful when using this method. It’s a great idea to get a professional to help you so you can avoid injury and damage to your system.

If you are comfortable with doing this method yourself, you won’t need much at all to make it work. You’ll need an air compressor rated 80-100 CFM, a coupler attachment to attach it to your air compressor and some protective safety goggles.

This method involves multiple steps that should be done in order and completed properly in order to ensure you keep yourself and your system safe.

A quick safety tip is not to exceed 80 PSI for PVC piping and stay under 50 PSI if you have polyethylene pipes and stay away from the sprinkler head you will be activating.

  • To begin, shut down your water supply and use the coupler attachment to connect your air compressor (which should be powered down) to your irrigation system.
  • Go to the sprinkler that’s the furthest away from where you have connected your compressor and turn the sprinkler on.
  • Close the backflow devices and slowly open the valve on the air compressor.
  • Very slowly, add more air pressure. Avoid doing it too quickly or you might damage parts of the system.
  • Keep adding pressure to the pipes until you start to see water start coming out of the sprinkler you’ve opened.
  • When you start seeing water coming from the open sprinkler head, you will want to slowly start activating the rest of the sprinkler heads, starting with the one closest to the one you’ve already activated.
  • When the water stops spraying from the sprinkler heads, turn them all off immediately.

Disconnect your air compressor and release the remaining air pressure that’s in the sprinkler system by opening and closing the valves to your backflow device or manual drain valves.

Close up all the valves and make sure you’ve closed up all the sprinkler heads and you’re all set.

This is one of the best ways because the air pressure will clear out the sprinkler heads completely but you need to make sure you keep the pressure low on your air compressor to start. If you run it too high, you risk blowing apart pipes, sprinkle heads or even pivotal mechanical components of your system.

If you want to hire a landscaping expert to blow out your system for you then it will likely cost between $50 and $120 but some landscaping companies have full winterization packages that include this plus other services to prepare your yard for winter. This is a great idea if you have multiple systems (like a pool or pond) that will also need to be changed over for the colder months.

Cleaning out your sprinkler system won’t take you very long and it is the best way to make sure your system is ready to go for the next year. One good way to remember is to set yourself a yearly alarm on your phone, put it on your calendar or just drain your system when you are done with it for the year so you won’t get caught before an expected freeze.

If everything is ready to go, you’ll thank yourself when it comes time to start up your sprinkler system for the year.

Diego Martinez

Diego Martinez, with a Bachelor’s in Mechanical Engineering from MIT, has been a leading figure in maintenance and facilities management for 16 years. He joined our editorial team in 2020, sharing his expertise in preventative maintenance, system optimization, and energy efficiency. Diego’s previous roles include engineering manager in manufacturing and consulting for facility management. He has provided practical advice and problem-solving strategies for maintenance issues. He is an enthusiastic cyclist and volunteers in community tech education programs.

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