To keep Rainbird sprinkler systems from freezing during the cold, winter months, many people winterize the system. This process removes water from the system to prevent ice build up and broken pipes. After winter is over, the system must be de-winterized before it can be used. De-winterizing the system is not as complex as winterizing it, but if the water fills into the system too quickly it can damage the sprinkler system.
Turn on the main water supply for the sprinkler system. Turn the ball or gate valve one-third to halfway open using pliers to allow the water to slowly fill the mainline.
Open the ball or gate valve all the way once you hear the water rushing through the pipe.
Press the "Manual" start button on the Rainbird controller. Turn the dial to "Zone 1."
Check the sprinklers in Zone 1 to make sure they are all working properly.
Repeat the process and turn the dial to Zone 2, then Zone 3 and beyond.
Look at the Rainbird controller and make sure the correct date and time are displayed. To set, turn the dial to "Set Current Date." Press the up and down arrows to set the day. Select the "Manual Start/Advance" button to go to the month field. Then press the up and down arrows to select the month. Repeat the process to set the year and time.
Reset the sprinkler watering times, if necessary. Move the dial to "Auto." Slide the program switch to A, B or C. Turn the dial to "Set Watering Start Times." Press the arrow keys to select the time.