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how to winterize your irrigation system with Automatic Drain Valves

Winterization is an important part of maintaining a properly running lawn sprinkler system. Where you live plays a big part in which steps you will need to follow. In this how-to guide to winterization, we will take a look at the steps involved in winterizing your sprinkler system in a cold climate. As a part of that, we will examine a method for removing the water from pipes and sprinklers using automatic drain valves. When you have finished reading this article, you will have the knowledge necessary to successfully winterize your lawn sprinkler system.

Step One: Turn Off The Water

First things first: when the time to winterize your irrigation system rolls around, you'll need to shut off the water at the main valve before doing anything else. By necessity, the shut off valve for your sprinkler system needs to be located in a place where it can't freeze up; this should have been done when the system was originally installed.

Step Two: Shut Down The Controller

Here's where things get a little less cut-and-dry. Automatic irrigation systems have a controller - or timer - that regulates when they turn on and off. Depending on what kind of controller you have, you may either choose to set it to "rain mode" or disconnect the power from it altogether.

Please note that you can always buy a more up-to-date, efficient controller or timer to save yourself a lot of time and money in the long run. offers the best selection and most competitive prices for lawn sprinkler system controllers on the market today.

Solid State Controllers

A solid state controller usually have digital time displays and generally use up a lot less electricity and power than their mechanical counterparts. Disconnecting the power from your sprinkler system controller means having to reset all of its associated settings when spring returns - not necessarily the simplest task in the world.

Solid state controllers tend to use very little electricity, though, so leaving them on - but in "rain mode" - will not cause a major spike in your electric bill. Therefore, if you have a solid state digital controller, use the "rain mode" setting and save yourself a lot of frustration down the line.

"Rain mode" means that your controller stays on, maintaining its settings, programming and keeping the time - but the valves simply don't come on. They can save you a great deal of time when it comes to winterization.

Mechanical Controllers

Mechanical sprinkler system controllers can be identified quite easily; they typically have a dial on them similar to one found on an analog clock. These machines do use up a lot of electricity when compared to solid state controllers. Most people find the cost of keeping mechanical controllers on throughout the winter overly prohibitive.

Instead of using "rain mode," then, it makes sense to turn off the power to a mechanical controller for optimal winterization performance. One more thing: if you have a pump wired to your mechanical controller, disconnect it. This can help eliminate the risk of the controller inadvertently kicking in and damaging the pump.

Step Three: Remove The Backflow Preventer And Take Care Of Risers

Next, you will need to remove the backflow preventer from your lawn sprinkler system. Once it's removed, drain all the water from it and store it someplace safe. Although you can always reinstall it once it's drained, that's usually a task best kept for the springtime.

While there's a chance that you'll be able to siphon water out of your irrigation system's risers, chances are that you'll have to pump it out. If so, a wet/dry shop vacuum is your best option; use duct tape to make the hose narrow enough to work properly.

Valves that are installed above ground should be drained of water and stored somewhere safe. Some people choose to use pipe heating cables on their backflow preventers and above ground valves. Keep in mind, though, that even when used properly such arrangements can fall victim to power outages and serious damages to your irrigation system can occur.

Removing A Backflow Preventer

As noted previously, removing your irrigation system's backflow preventer and storing it for the season is a smart move when you're completing the other steps involved in winterization. How do you remove a backflow preventer, though? With any luck, the one that you have is held in place with union connections. In this case, you'll just need to uncouple them on either end of the backflow preventer, just before the bends in the piping. Once it's removed, storing it will be simple. You can use insulation on the exposed ends of the pipe to keep them safe from harm - and to keep critters and debris from inadvertently getting in.

If you don't have union connections in place, though, you're in for a little bit more work. The people who have the biggest trouble removing their backflow preventers are the ones whose system doesn't use union connections. In this case, you'll have to cut the backflow preventer out manually. It's definitely more work, but the good news is that once that's done, it's done. When spring rolls back around, you can reinstall the backflow preventer for your irrigation system using union connections; the next time you need to winterize your lawn sprinkler system, it will be considerably easier.

Step Four: Removing Water From The Pipes And Sprinklers

Now comes the most important step of the winterization process: removing all of the water from the system's pipes and sprinklers using the drain valve method.

The Drain Valve Method

In order to explain the process more clearly, we will highlight the pertinent facts and steps involved in using the drain valve method to drain the water from your lawn sprinkler system in small, easy to grasp sections below.

  • Location - It's critical to have properly placed drain valves. Basically, you will need a drain valve at every low point in your piping system. Additionally, a drain valve is needed at every high point that doesn't have a sprinkler so that air can escape; otherwise, the water won't drain.

  • Organization - If you're using manual drain valves, do yourself a favor and clearly mark down where each valve can be found on an easy-to-read chart. Keep the valves in a box and store it somewhere where it will be easy to find when it's needed.

  • Strategy - When your lawn sprinkler system was installed, optimally the remote controllers were placed just above the lowest point in a circuit. That way, you can install the drain valves at the same place as the controllers, making it much easier to winterize properly. About 1/4" of slope is needed per foot to drain the pipes effectively; in the best case scenario, you'll only need one drain valve per lateral.

  • Automatic Drain Valves - You can streamline your winterization process by using automatic drain valves. Assuming they are on the ends and the low points of your sprinkler system, automatic drain valves work to drain excess water when the pressure gets below 10 psi. Activate a station to release the pressure and to get the automatic drain valves going. You'll find that they save you a great deal of time and frustration when the time to winterize your irrigation system rolls around.

  • Water In The Valves - Since water won't drain all the way out of the valves, it will be necessary to remove them. Although it's possible to take them apart and dry them manually, it is not a practice recommended for the average, everyday DIYer. Choose valves with unions to make removal easier. After removing the valves, cap the ends to keep garbage and pests out.

  • Water In The Sprinkler Heads - Sprinkler heads with built-in check valves don't drain completely; neither do side inlet sprinklers. If you're unsure what kind you have, remove a sprinkler's cap to see if there's water down in the sprinkler body. If so, you'll need to remove it and shake it out thoroughly. Otherwise, you could try using a wet/dry shop vacuum to suck the moisture out.

A Note About Backflow Preventers

Whether you live in a temperate or a cold climate, you can save yourself a lot of hassle - and make winterization much easier - by insulating your irrigation system's backflow preventer. In cold climates, occasional late and early season freezes occur and can damage your equipment. Using a small amount of self-sticking foam insulating tape - without blocking the drain outlets or the air vents - should be sufficient. Otherwise, try using some R-11 fiberglass insulation. Wrap it around the backflow preventer, then use duct tape to secure a plastic bag around the whole thing. Don't secure it too tightly - just tight enough to keep it from blowing off.

Practice Makes Perfect

As outlined above, it is easy to see that winterizing your irrigation system doesn't have to be an impossible task. Doing it yourself can save you a great deal of money, and with every passing season you will become more skilled at it. Having the right equipment and parts can also help tremendously; you can find the best controllers/timers, for example, by visiting Remember, also, that once you've insulated all of your pipes and backflow preventers properly, you will be set for some time and won't need to repeat the process every single year.

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