A harsh winter freeze could damage your irrigation system--and your wallet--if not properly drained. You'll want to winterize or drain the components of your irrigation system so no residual water remains. If left untended, water inside the outdoor pipelines might freeze and expand, causing cracks and breaks in the system. Proper shutdown of your sprinkler system will save you money and headaches.
Grasp the lever of the main shut-off valve inside your home and turn it perpendicular to the pipe to shut off the outside water line from the main water supply. If you can't find the main shutoff, locate the pipes on the exterior of your home. The main shut-off valve is located close to these pipes on the other side of the wall.
Seat a large bucket just below the main drain valve, which is near or on the main shut-off valve. Twist open the drain and allow water to drain into the bucket. If the bucket fills, turn the drain off, empty the bucket, reseat the bucket and turn the valve back on until all the water is drained. Allow the drain to remain open with the bucket underneath for the duration of winter.
Insert a flat-head screwdriver into the screws of the test cocks on the side of the backflow prevention unit, which connects the main line to the sprinkler system. Twist open the screws until each groove is parallel to the cocks. Leave the test cocks open and allow the water to drain.
Move the two backflow prevention ball valves to the open position or parallel to the pipe, not perpendicular.
Screw off the drain cap located at the bottom of the prevention unit. Allow water to flow from the unit. Keep the cap in a safe place throughout the winter season.
Insert the flat-head screwdriver into the screws of the test cocks and twist them to a 45-degree angle after the unit drains. Grasp the two ball valves and move them to a 45-degree angle as well.
Locate the sprinkler valve box or boxes in your grass. The boxes house the sprinkler valves and have green lids. Remove the lid and loosen the solenoid of each valve by twisting it counterclockwise. In one of the boxes is the end valve. Open the end valve completely and allow it to drain.
Open the box to the controller or timer and turn the unit to "Off" by twisting the knob or pressing the "Off" button.