Winterization (Blowout)

Safeguard your system for the winter with our complete and certified blowout service.

Naiad service van

Watch: Sprinkler System Blowout

What is Winterization?

Before the first freeze hits Calgary, you should perform a blowout to remove the water from your irrigation system.

Frozen water expands and can damage the vital components of your system or burst its pipes. Winterization is also known as a “blowout” because we blow out most of the water from your system, leaving it empty and ready for hibernation.


Don’t Wait Until the Last Minute

Waiting until the temperature hits below zero is not recommended, as this can be enough for considerable amounts of ice to form inside your irrigation system.

Calling ‘quits’ on the summer season can be sad, but paying later to repair your system because the winterization was not done on time does not make it any better. Protect your investment and schedule a winterization service in time.

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Naiad service blowout
Naiad service blowout

Get Ready For Winter

Blowing out lines is no easy task. Make sure you hire this service from a certified contractor.

We recommend making sure that your irrigation system is running properly. If you experienced any issues in the summer it might be a good idea to have it checked or repaired before your winterization service.

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Winterization Frequently Asked Questions

Here are a few frequently asked questions about this process:

How do I winterize my underground sprinklers?

  1. Shut off the water supply to your sprinkler system. The shut-off valve for the sprinkler system is usually just downstream of the water meter.
  2. Hook up a compressor of at least 70 CFM (cubic feet per minute) to your sprinkler system’s blowout port (typically a garden tap) and expel most of the water from the irrigation lines and sprinklers. Do not exceed 80 PSI.
  3. As the system winterizes, walk around the property, looking and listening for possible leaks. Air acts differently than water, and sometimes you may be able to spot or hear a leak that you were not aware of.
  4. After winterizing the system, shut off the second isolation valve outside if you have one and leave the blowout port open.
  5. If you have a drain inside the house on the main water line for the irrigation system, please open it and leave it open for the winter. Do not be alarmed if some water comes out; that’s normal. It is best to have a pail to collect the water. After an hour, it should stop dripping. If water keeps dripping, your shut-off valve for the irrigation mainline is not working correctly.
  6. Allow your system to “dry run” its irrigation cycles over the following week before turning off your irrigation timer. It is best to have the solenoids (the electrical switches that control your system’s secondary valves) activated a few times after winterizing the system.

Check out our video on this to learn more:  https://youtu.be/IzvvdG_eylE

Do you have to winterize an underground sprinkler system?

Yes, you do.  Every fall, most of the water must be expelled from the irrigation system. Otherwise, it will freeze, expand, and damage your underground irrigation system in the winter.

What do winterizing sprinklers mean?

When water freezes, it expands. Thus, most of the water must be expelled from the irrigation system before the water can freeze. This is called an irrigation system blowout because a compressor blows out most of the water. Once most of the water has been removed from the sprinkler system, it is ready for winter. A few clients ask if we put antifreeze in the lines.  We do not.

When should I winterize my underground sprinklers?

A sprinkler system should be winterized before overnight temperatures fall below zero degrees Celsius.  For us here in Alberta, we recommend winterizing your irrigation system before the end of September.  We have had a few years when the overnight lows have been cold enough to damage the main waterline for the irrigation system as early as September 28th.  Ultimately, you can run it later into the season, but there is always the risk that a cold overnight low could damage your irrigation system.  The bit of pipe that goes from the house to the valve box is most at risk. That bit of pipe is exposed to the elements and can freeze faster than the pipes or sprinklers in the ground.

What if the overnight low is cold, and my irrigation system has yet to be winterized?

What we recommend is the following:

  1. Shut off the water to the sprinkler system.
  2. Find where the mainline comes out of the house and open any garden taps or remove any plugs attached to the main water line of the underground sprinkler system to allow the water to drain out.
  3. If you have a ball valve on your mainline, leave it open. (If Naiad Irrigation Systems Ltd. installed your system, there is almost definitely a ball valve.)  Trapping any water in the ball valve by shutting it off will cause it to burst as the temperature drops and the water freezes.
  4. Open your valve box, open any bleed screws, and loosen any solenoids (turn counterclockwise). If you cannot find the valve box or identify these parts, just run all the zones manually using your sprinkler timer. This will accomplish the same thing.  By turning on the zones and opening the hose bib attached to the mainline, gravity will allow the mainline to drain, protecting the exposed bit of pipe.
  5. We have seen some clients insulate the valve box by putting something over it, such as a thick blanket or some pink insulation. That may help keep the warm air in the valve box.
  6. Lastly, if there is a lot of snow in the forecast, please mark where the valve boxes are for your irrigation system. That will help your irrigation professional find the valve box under the snow.

Is all of the water removed from the sprinkler system during winterization?

No, but the majority of it is.  There is always a little left over.  The point of winterization is to remove the majority of it, and the remainder will not be enough to damage the underground sprinkler system.

Also, sprinklers are not watertight.  As easily as water leaves the nozzle when the sprinkler system is on, water will return through it, too, via snowpack melt and/or rain.  Water entering your system gradually throughout the winter is unlikely to cause damage.

Lastly, rotor-style sprinkler heads have gears and other moving parts inside.  Air acts differently than water, and blowing hot air through a rotor head for extended periods can damage the gears and shorten the lifespan of the rotor head.  This means you could damage your irrigation system by blowing it out for too long in an attempt to expel every last drop of water.


Winterization / Blowout – Terms & Conditions

Regarding the service commonly referred to as a Sprinkler Winterization or “Fall Blowout”, depending on the system layout, parts may need to be disconnected in order to ensure that the system has been winterized properly.

Because the system no longer has water running through it, Naiad Irrigation Systems Ltd. (hereafter referred to as “Naiad”) cannot guarantee that any components that may or may not have been disconnected and reconnected during the winterization process will be reconnected to the point in which they could be deemed as watertight.

Furthermore, in order to allow certain irrigation systems to drain properly, some exterior components of the system may be left open after the service has been completed to prevent any potential damage to the system over the winter.

With this being the case, Naiad cannot and shall not be held responsible for any potential and/or actual damages to any persons and/or property due to improperly installed, malfunctioning, or otherwise leaking/open components.

Please Note that Naiad Irrigation Systems is not responsible for any damages or potential damages due to freezing conditions. As a result, Naiad can only guarantee services booked on the first day that we are servicing that area. Appointments booked for the second or third day that we are in the area are highly susceptible to freezing conditions which is why we highly recommend always booking for the first day we are servicing your area to avoid any complications.

Should a system be frozen at the time of the winterization, Naiad will return the following week to attempt to winterize the system again. Notice will be sent to any clients who have frozen systems informing them of the situation.