How to Shut Down an Irrigation System for the Winter



Irrigation is a great way to keep your lawn and plants looking amazing. The ease of use, reduced yard maintenance and look of your yard make it a great investment for your property. During the growing season you set the system and forget it. There is however, a bit of maintenance at the beginning and end of each growing season. We'll go over how we shut down irrigation systems for the winter.



How to Blowout and Winterize Your Irrigation System for the Winter




Tools Required:

  • 80-100 CFM Compressor

  • Proper rated hose and coupler

  • Hose adapter to hook up to the main line

  • Pressure regulating valve with shut off at the end of the hose

  • Safety glasses & gloves


Before You Begin

Warning: If you've never been trained on how to winterize your system, it's best to leave it to a professional company. Improper blowout can result in pipes being burst, fittings coming loose, valves and heads being damaged and more, leading to hundreds even thousands of dollars worth of damage.

  • These steps are for those in Canada where we tie our irrigation systems into the the house/building spigot and not directly into the properties water line with meter and backflow preventer.

  • Compressors should not exceed 50psi for Polyethylene pipe and 80psi for PVC pipes. DO NOT EXCEED these at any time unless you know its safe to

  • Do not pressurize the main line without a valve being open

  • Do not allow the system to blow out completely dry, it is okay if there is a bit of water left in the system

Let's begin!



Step 1: Inspect the system for leaks and damage

Before you begin the blowout, you'll want to inspect your system for leaks and damage. Do a walkthrough and inspect the valves and visible mainline for signs of wear, damage and leaks.


Step 2: Remove the irrigation systems main line from the building spigot

Turn off the house spigot that is connected to the irrigation system's mainline. Remove the mainline connector from the houses spigot.


Irrigation tied into house spigot
The irrigation main line typically ties directly into these house spigots

Step 3: Attach compressor to the irrigation systems main line

Attach the compressors' hose/fitting to the mainline that was attached to the spigot and open one valve on the irrigation system manually. Do not turn on the compressor yet.


Step 4: Check compressor settings

Check to ensure the compressor is set to the proper PSI rating, leave the compressor hose shutoff valve in the closed position.

Polyethylene pipe should be less than 50psi - Do not exceed 50psi

If your system uses PVC it should be less than 80psi - Do not exceed 80psi


Step 5: Turn on compressor

Turn on the compressor, then slowly open the hoses shutoff valve, make sure one irrigation zone valve is open.

Irrigation blowout compressor
This compressor might not be sufficient

These small compressors typically do not hold enough air for a proper blow out.

You can try it but you'll have to let it re-fill often. You'll want a CFM between 80-100


Step 6: Blow out each valve

If done correctly and you used the right pressure, the heads should pop up. The heads will start blowing out water, then turn into a mist and then finally air. Once it reaches the air stage, immediately close the hoses shutoff valve. Then close the irrigation systems zone valve.


You can move onto the next zone by opening another valve.


Repeat this process through each zone. Each zone should take 1-3 minutes to blow out before the air stage commences.


**Do Not let it stay in the air stage, dry air movement causes heat and can damage the system so immediately after the mist stage is completed, turn off the air supply. A bit of water left in the system is fine and will not damage it.



Step 7: Turn off compressor and pack up

Once you're finished blowing out each zone, turn off the air compressor and pack up. Open each zone valve once more to release any pressure built up in the lines.


Step 8: Place bag over rain censor and mainline connector

Place a bag over the rain censor and mainline connector, and use an elastic to secure the bag in place. We've seen spigots leak during the winter and fill the main line with water, leading to a cracked main line, fittings or valve.


That's it! You've successfully completed the blow out. If done correctly your system should be safe for the winter.


For more great information on irrigation, water features, hardscaping and more, you'll find some great information here.


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Have you ever had issues in the spring from a poor shut down? Let us know by leaving a comment below!


If you're in the Winnipeg area and need your system startup or shutdown completed, we can help!


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