Home Owners: Winterize Your Lawn Irrigation System On The Cheap!

Soon the snow will be falling.  The dried leaves are starting to drop and halloween night seems right around the corner. When the yard begins to turn crispy and brown, it may be time to think about closing down your below ground yard watering system and  winterizing it for the colder months ahead.  Besides, the snow will start flying soon and you'll need to focus on getting the snowblower fired up and ready for action!

While many folks opt to grab the phone and have a lawn irrigation contractor come and winterize the underground lawn sprinkler system, it isn't really that difficult to do so yourself.  You do not really need any fancy tools aside from what's in a standard tool box.  Needle nose pliers and channel locks can also come in handy.  In most scenarios no special tools are essential to complete the job.  For sure though,  you'll need an air compressor.  For some individuals it's a lack of an air compressor that puts this project on the "Call A Contractor" list.

This project really isn't all that difficult to do.  It depends, really, on the size of the lawn and irrigation system.  It is a live and learn kind of gig, meaning it will get less difficult the more times you do it.  If you're able to ensure complete the initial attempt without too many snags you will be all set for future winterization projects with no problems at all.  

At regions where the ice level freezes below thee ground and down to your sprinkler pipelines, blowing out the sprinkler system thwarts water from icing inside your water lines and rupturing them. Care must be takes, however because doing this wrong could lead to busted up water lines, melted pvc pipes or maybe pneumatic compressor oil flowing into your well.

Shut off the water supply valve then open the drain valve. After the supply line drains, close the drain. The drain valve should be closed once the water stops draining. Find an air compressor that is the right size.  60 cubic ft per minute of pressure is usually good enough for residential use. For non-commercial work many building contractors choose compressors in the one hundred twenty-five psi foot range.

Take the irrigation backflow protection mechanism down then hook up the compressor to the pipes where it was mounted. Be vigilant never to send air inside the pumps where seals can easily become ruined. Shoot air within the plumbing until eventually all of the liquid is blasted through. Take caution that the compressor beak or piping isn't growing to too hot from air friction. Flip off the compressor, close the valve off then move near the upcoming valve in line.


Keep doing this until you've covered all the valves. It's usually a good idea to repeat the process of blowing out each valve segment at least 2 times to make sure they are all clear and free of any residual water. Open the last valve or the valve at the highest elevation. Close the rest of the valves. Dependent on the average temperatures in your area you can leave the backflow device disconnected and bring it indoors or simply insert it right back in place.  Some backflows may have a bypass and may not need to be removed in order to blow out the lines. Many folks choose a backflow cover or security cage to safeguard the irrigation backflow instrument.  Backflow insulation is also popular, especially in the spring and fall.  In very cold areas you may need an electric heat source if you intend to leave the backflow outside all winter.

Last but not least: the backup plan!  If you happen to nerf the winterization project and discover come spring that the backflow device in your yard is leaking like a sieve, it may have frozen in the cold.  Frozen water expands and does bad things to seals, o-rings, gaskets, springs and other sensitive mechanisms.  Buying a brand new backflow preventer is always an option, but they are super pricey.  If you are a DIY type you can try to fix it yourself using a backflow repair kits or backflow parts designed to rebuild the device.  Here's a video with some details:

Just remember that repairing a backflow device yourself is going to take some skill and basic knowledge of how one of these gizmos works.  You can always check out ZFebco, Wilkins, Watts etc websites for teardown manuals on the different models as well.  Good luck and may the force be with you!