An irrigation controller set to off does not remove water from buried lines, valves or a backflow preventer. Before freezing weather, find out whether your system is designed for manual draining, automatic draining or a professional compressed-air blowout—and use that method rather than guessing.
Locate the irrigation shutoff, controller, backflow assembly and any drain valves. If you have the installer’s diagram, keep it nearby. Identify whether the system has manual low-point drains, automatic drains or is intended to be cleared with compressed air. The sprinkler manufacturer Hunter describes these as different winterization approaches; the right method depends on how the system was installed. If you cannot identify the system type, do not open unknown valves or run the controller thr...
A manual-drain system relies on valves at the low points to let water out. An automatic-drain layout uses components designed to release water under specified conditions. Neither method should be assumed to work on a system designed for a compressed-air blowout. Follow the manufacturer and installer instructions for your actual system. Compressed air can damage pipes, valves and sprinkler heads if pressure or flow is not controlled, and can create a serious injury hazard. Do not use an unregula...
The backflow preventer and exposed piping are vulnerable because they sit above grade. After the water supply is shut off and the assembly is drained as directed, follow the device manufacturer’s guidance on valve position, test ports and insulation. Do not wrap an assembly that still contains water or rely on a cover to protect an undrained device. If the assembly is damaged, leaking or has a failed test, contact a qualified irrigation or plumbing professional. Backflow equipment protects drin...
Turn the irrigation controller off or use its rain/shutdown mode as directed, but keep any required freeze protection or monitoring enabled if the manufacturer specifies it. Mark the outdoor water shutoff so household members know it controls the irrigation branch. Do not switch off a valve that also serves another system without confirming the piping. In spring, open valves slowly and inspect each zone for cracked heads, leaks and low pressure before returning the controller to its schedule. A...
No. Turning off the schedule does not remove water from pipes and backflow equipment. Identify the system’s designed draining or blowout method and complete that shutdown before freezing weather.
Only if the equipment and system instructions permit it and you can control the required pressure and flow safely. Improper blowouts can damage components or injure people; hire a qualified irrigation professional if unsure.
Follow the backflow device and irrigation-system instructions after the assembly is properly shut down and drained. Insulation alone does not protect water trapped inside the device.