You Need to Winterize Your Sprinkler System.

Your drip or sprinkler system will run all spring and summer, but as the first frost approaches, it’s important to think about the steps you need to take to hibernate your system for the winter.

Your sprinkler or drip system is most likely made of PVC, polyethylene, and plastic. While these materials are quite resistant to weather changes, water flowing through them is not. Water becomes ice, and this is a problem because even strong materials are not resistant to the pressure created by the expansion of water into ice. Irrigation pipes are installed under the beds, grass and throughout the yard. Finding a leak is a pain I wouldn’t wish on anyone.

Preparing for winter is a hassle-free but vital task, and it’s not an overly complicated process. It’s also worth doing sooner rather than later, and it’s worth getting insurance in case you suddenly get cold unexpectedly.

To protect your system, your first step is to get rid of the water. Some systems are now built with drains at the lowest point of the system to proactively remove standing water, but most of us will have to blow out or drain the water ourselves.

Determine your drain mechanism

Each system is built differently. Some systems have a drain located near the sprinkler shut-off valve, and it may be located in your home – usually in the basement, near the water heater. It will look like a hose connection on the spray line.

Other times, your manifold has a fitting specifically designed to connect to an air compressor, so you can literally blow all the water out. Your collector is usually found in the ground, in a green and black plastic box next to the sprinkler timer, and looks a bit like an octopus. This is where your timer wires connect to all of the controllers for each sprinkler or drip line. Sometimes the manifold will have a drain valve, which again will look like a drain.

Get help from a plumber

Since your average homeowner or renter is not a plumbing expert, consider paying a plumber an hour of his time to check out the system and get his advice on how best to winterize it. In many places, backflow requires an annual inspection, so now is the time to ask. You can also simply hire a landscaping company or plumber to start preparing for winter right away.

Understand your pipes and valves

Your sprinkler system is a collection of pipes and valves. Pipes direct water and valves close or open access to the pipes. Your pipe starts from the water supply and there is a valve there. When open, water flows into the sprinkler line. There will be more valves along the line, such as on the manifold or in each of your garden boxes. Each of the controllers in the manifold is a valve that opens and closes on a timer. When the valve is closed, water can get in there, and you don’t want that water to freeze.

Understanding these valves will help you understand how to get rid of the water as it will require opening and closing them. When you drain part of a pipe, it only happens between two closed valves.

Your sprinkler heads likely contain something called a “check valve” that allows water to flow back into the pipe, and you can access them by simply lifting the sprinkler heads by hand.

Valves aside, water naturally flows to the lowest point, so you also have water sitting in pipes underground. Typically, these pipes are located below the frost line, which varies from section to section. These pipes are supposed to be protected from frost. Still, it’s better not to take risks.

Your system may also have something called vacuum breakers installed, which are part of the backflow prevention to prevent water from your pipes from flowing back into the city water. You will need to open these vacuum switches during the draining process.

How to drain the system if you have an internal drain

Start by turning off the sprinkler system’s main valve closest to the water supply. If you have a drain nearby, place a bucket under it (also not a small one, depending on the size of your system). Open the drain and let it run until no more water comes out, emptying the bucket as needed. Leave the bucket there for the next step.

Next we check the vacuum switches. They may have drain caps and you will have to open them to release the vacuum. Remember that since the water supply is turned off, this water cannot flow back into the city water. More water should flow out of the main drain pipe. This drain should remain open all winter, so leave a bucket there to catch the flow.

How to bleed the system if you have a bleed fitting

Start by closing the main water valve near the water line to prevent more water from entering the sprinkler system. Make sure all the valves between the one you just closed and the purge fitting are open, and open one of the main sprinklers or drip lines. Make sure all the valves on the other side (where the water comes out) are open. Insert the air compressor into the fitting and turn on the air supply. You will hear water moving down the sprinkler line, but at some point all the water will disappear and only air will come out of the sprinkler or dripper. Check all ends of this line and then turn off the air supply and close the sprinkler line, leaving the valves open. Now open the second spray line and repeat the step. Do this until all sprinkler lines are clear of water.

At this point you can close the valve after connecting to the manifold. If your house has a drain, open it, place a bucket under it, and return to the fitting. Blow out the air and all the water between the manifold and the water line should drain out. Leave the drain open over the winter, open the manifold valve, and make sure you screw the cap back securely onto the outlet fitting.

Reverse process in spring

When you’re ready to run your sprinklers again in the spring, you’ll want to make sure the drain valve is closed and then test the system. When you first let the water back in, you may hear a loud noise called “water hammer”; It’s just water displacing air from the system. This is completely normal and is only a problem if it persists.