Winterizing Your Sprinklers: The Manual Drain Method Don’t let the winter freeze catch your irrigation system off guard! In this video, we walk you through the final, crucial step of winterizing your sprinkler system. Even after the water is shut off, your valves need to be electronically opened to allow the underground pipes to drain completely. We show you how to use your controller's "Manual Start" function to cycle through every zone, ensuring no water is left trapped to freeze and cause expensive pipe bursts.