How to Winterize Your Sprinkler System

There are three basic methods for draining leftover water from your sprinkler or irrigation system: manual drain, automatic drain and blow-out. The method you use depends on the type of irrigation you have in place.

If you’re not sure, or don’t feel comfortable winterizing yourself, contact a professional for help. Keep in mind that you won’t be alone in requesting assistance, so plan ahead. Prepare early when you live in a region where frost penetrates deep underground.

Some irrigation systems are equipped with manual drainage. These systems allow you to empty excess water from the system by simply opening a valve.

If you have manual drain irrigation, follow these steps:

• Shut off the water supply to the system.
• Then, look for the manual valves at the ends and low points of the piping.
• Open all the valves and drain the water from the system.
• Make sure you also drain the backflow device.

Some sprinklers are equipped with check valves. These devices allow water to only flow one way. If you’ve got check valves on your system, try raising the sprinkler heads. This should let water drain out of those mechanisms. Once you’ve drained the entire system, close all the valves.

An auto drain system has valves that automatically drain water from the pipes. This happens only when the water pressure falls below a certain number of pounds per square inch.

To activate an automatic drain function, follow these steps:

• Turn off the water supply.
• Briefly run one of the sprinkler heads to relieve the water pressure in the system.
• Automatic draining should begin, clearing the pipes of excess water.

You may still need to drain the water between the shut-off valve and the backflow device. If the sprinkler heads are equipped with check valves, empty them separately.

The final way of draining an irrigation system is known as the blow-out method. To drain the pipes, you force compressed air through the irrigation system. This discharges excess water through the sprinkler heads. It works if you have the proper irrigation system to handle the pressure.

The blow-out method is potentially hazardous. It can damage both the irrigation system and the person attempting it. It’s vital to take proper safety precautions when using this method.

If you’ve never worked with compressed air or blown out an irrigation system before, please consult a professional. You’ll save yourself from frustration, possible injury and repair costs.

Should you feel comfortable and qualified to drain water this way, you’ll need these materials:

• An air compressor rated at 80-100 CFM
• A couplerthat fits your irrigation system
• Safety glasses

Put on your safety glasses, then assemble your compressor and coupler. For clarity, these instructions are provided in two sets.

Follow these steps to begin draining water from your irrigation system:

• Shut down the water supply and connect the air compressor to the irrigation system using the coupler. Avoid blowing compressed air directly through the backflow device.
• Find the sprinkler station highest and farther from the compressor and turn it on.
• Close the backflow valves.
• Slowly open the valve on the compressor.
• Gradually add more air pressure. That way, you can cut off the air supply quickly if you need.
• Keep going until you start seeing water come through.
• Do not exceed 80 PSI for PVC piping or 50 PSI for polyethylene piping. When blowing out your irrigation system, don’t stand near an active head.

Once you’re seeing a spray of water from the active irrigation head, follow these steps:

• Starting with the farthest irrigation head and working your way closer to the compressor, activate each head in turn.
• Shut off each head when the spray of water ends.
• When you’ve finished draining all the irrigation heads, disconnect the compressor.
• Release any remaining air pressure from the system.
• Open and close the valves on the backflow device and/or manual drain valves. This is to release any pent-up air pressure.
• Assure all the valves are closed when you’re done.

Your irrigation pipes and sprinkler heads should now be clear of excess water. Please reach out to a pro if you need additional assistance.