Getting Your Sprinkler System Ready for Winter

Living in Southern Ontario we know that our winters can be volatile with temperatures ranging from mild to bitterly cold. We know that if we don’t properly drain our exterior water pipes, burst pipes can happen, leaving us with damage which will need to be fixed next spring. The same rules apply to your in-ground sprinkler system if the pipes are buried above the frost level.

What Can Happen If I Don’t Winterize Properly?
Even if you drain the water from your irrigation pipes, any remaining water could freeze. PVC pipes are particularly susceptible because they are made from rigid plastic. The water will freeze, expand, and crack the pipes, especially around the fittings from pipe to pipe. Many companies will use a more durable and flexible option – black, polyethylene pipe – for areas which get very cold in winter, but freezing, expansion and cracking is still possible. Beside pipes, your backflow assembly could also be damaged with ice damaging internal parts or cracking the outside housing.

Depending on your type of irrigation system, there are 3 different ways to remove the water before winter:

Automatic Drain
If your system is fitted with automatic drains, they will open and drain if the pressure in the pipes falls below 10 PSI. To do this, turn off the water supply to the sprinkler system and then activate a station to reduce the pressure in the system, which will open the drains on the mainline. There should be another valve between the backflow device and the main water shutoff. Open this to drain the remaining water, opening the test cocks on the backflow device as well. If your sprinkler heads have check valves, pull up on the sprinklers to allow any remaining water to drain out of the sprinkler body.

Manual Drain
If your sprinkler system is a bit more basic, you will have manual drains instead of automatic. The procedure is essentially the same as with automatic drains, except you will have to open the drains yourself.
Even with both of these types of drains, there is still a chance that water will be left in the pipes, especially if pipes have settled.

Blow-Out Method
The blow-out method is the only way to ensure all water is removed from your sprinkler system, but it can be dangerous and it’s recommended to be done by a professional because it uses compressed air to blow through the pipes at a maximum of 80 PSI. Call Nutri-Lawn Burlington Irrigation if you are interested in this draining method.

Rain Sensor
If your in-ground sprinkler system has a bowl-type rain catcher to sense rain, drain the water and then cover with plastic for the winter. If your rain sensor uses discs, it’s best to remove and store them so they don’t freeze.

Outdoor Controller
If you have a controller mounted outside, turn the dial to “off,” but leave the power on. This will ensure the heat from the transformer will keep it from freezing, but will ensure the field system won’t try to turn on.