Winterizing Your Sprinkler System/Backflow

Houston is not known for its cold weather but if there is one thing the last couple of years has shown us it is that no matter how hot it is getting in the summer months we can drop below freezing more than just a few times during the winter.  As many of you know these freezing temperatures can wreak havoc on your irrigation system because the pipes are not buried very deep and the backflow device, if you have a Vacuum Breaker, is above ground.  Because of this, understanding how to winterize your backflow device is very important in order to avoid costly repair bills or the possibility of cross contamination and Taylor Irrigation Service is here to help just in time.

The backflow device is the most important component of your irrigation system because it protects your family’s tap water from harmful contaminants that are present on the lawn, things like fertilizers, pesticides and animal droppings.  These contaminants can be sucked into the irrigation system when the sprinkler heads finish spraying and go back into the ground.  Your backflow device acts as a stop gap between the water that is contaminated and your drinking water so it is very important that your backflow device is installed up to code and that it is functioning properly.

There is a great deal of misinformation out there as to how you properly winterize your backflow.  The most common misconception (That you should turn your backflow off during the winter) actually ensures that the backflow will break and will therefor cost the home owner many hundreds of dollars in repairs.  Winterizing your PVB properly is easy, will save you a great deal of money and only takes one or two minutes.

To properly winterize your backflow you MUST have a cut-off valve.  A cut off valve is most commonly a ball valve and will be located in a valve box near your meter or at the foot of your backflow.  Cut-off valves are standard components of an irrigation system and are currently state code though many older systems and a great many systems that were not installed by a licensed contractor may not have one.  If your system does NOT have a cut-off valve then leave the backflow on and simply wrap it with towels during a freeze.  DO NOT turn the backflow off as this will significantly increase the chances of freeze damage and will usually result in a crack on the inside of the PVB.  We repair many PVBs every year that were damaged from home owners, landscapers and even misinformed irrigators turning the backflow off.  Once again; if you do not have a cut-off valve then leave the backflow device alone and simply wrap it in towels during the freeze.  DO NOT turn it off.

After locating your cut-off valve step one is simply turning it off.  Not all systems will have a ball valve as the cut-off, some will have a gate valve (like the one on your hose bib) but a ball valve is the most common.  A ball valve will only turn a quarter of a turn in either direction and is open (or on) when the handles are in line with the flow of the pipe and is closed (or off) when the handles cut across the flow of the pipe.  If you have a gate valve then just turn the valve clockwise until it is hand tight.

The next step will require a standard small flat head screw driver.  With screw driver in hand, standing in front of your backflow device once again we are going to focus on the test-cocks.  The test-cocks are a pair of small nozzles that are used to test or drain the main cavity of the backflow.  Each of these test-cocks will have a small screw in the center.  Those screws, as with the ball valve, are open when the slot of the screw is in line with the flow of the water and closed when the slot cuts across it.  Use your screw driver to turn each of the test-cocks one quarter of a turn so that they are open (the slots should be horizontal).  This will allow the water inside of the backflow to drain from the unit.  DO NOT turn the screws more than a quarter of a turn or remove the screws from the test-cocks.

 

When the draining water begins  to slow we take the final step.  Leaving the test-cocks open to drain we are simply going to turn each of the ball valves on the backflow device to a forty-five degree angle (meaning that the ball valve itself is half open/half closed).  There will be one ball valve at the bottom of the backflow and one ball on the side of the backflow.  In any order turn one ball valve to a forty-five degree angle and then turn the other to a forty-five degree angle.

Success!!  You have now properly winterized your backflow.  If you do not plan on watering your landscape during the winter then you can leave your backflow winterized until the temperatures start to climb.  If you do water during the winter then you will perform this winterization process before each freeze.  It is always best to consult your personal landscaper or horticulturist to find out what the winter water requirements of your landscape are before making this decision.

To make your sprinkler system functional again you simply need to: 1) Open your cut-off valve (this is going to shoot water out of the test-cocks but that is okay, we want to let any air in the line escape.  2) Close the test-cocks with a screw driver (screw slots vertical) which will stop the water from spraying out of the backflow.  3) Return both ball valves to the full open position (handles in line with the flow of the pipe).  Your PVB will once again look like the one in the image featured at the very top of this article.

As always, Taylor Irrigation Service, Inc is here to help so if you need any advice or help winterizing your system then please don’t hesitate to contact us at: info@taylorirrigation.com

From all of us here at TIS to you and yours… Happy Holidays!