How To Winterize Lawn-Sprinkler Systems

February 16, 2015

In northern Utah, it’s time to winterize lawn-sprinkler systems before temperatures drop any further. Winterizing is essentially the process of removing any residual water from the pipes, sprinkler heads and valves, preventing pipes from cracking or rupturing. In addition, protecting the system’s automatic controller is critical in preventing costly damage. Also known as “blowing out” the system, there are several ways to accomplish this task, depending on your sprinkler’s configuration.

Manual Drain Valve Method of Sprinkler Winterization

If your system has a manual drain valve, it is typically located at the lowest point of the main line (there may be more than one). Ensure the system is turned off from the main line’s shutoff valve. Slowly open the manual drain valve(s) and allow the water to completely drain. Locate the backflow preventer and open all test cocks to depressurize the system. If your system has check valves, pull up on the individual sprinklers to allow water to drain from each.

Winterizing Sprinklers with the Automatic Drain Valve Method

If your irrigation system has automatic drain valves, the procedure is slightly different. Typically these drain when the system pressure drops to a certain level, usually 10 PSI. The automatic drain valve is spring-loaded and designed to remove water each time the system cycles off. As such, there will likely be little water to remove unless a drain has become clogged during operation. Remove automatic drain valves and disassemble them, as there is no way to remove water from inside the valves unless you plan to use compressed air.

The Blow-Out Method of Irrigation System Winterization

This approach, although highly effective, can also be dangerous. Always wear eye protection and stand well clear of irrigation pipes and valves. Use a minimum two horsepower compressor that can produce between 10 and 25 cubic feet per minute air pressure. Be sure that at least one or more valves is open and take care never to exceed recommended CFM, as damage or injury can occur. It is important to note that this method is not recommended as a DIY process, unless you are familiar with your specific irrigation system and its components.

Be aware that your system may utilize some combination of manual and auto drain valves. If you aren’t comfortable with handling this task on your own, All Green Pest Control and Lawn Care of Provo provides full-service lawn care and pest management services. Their highly skilled technicians can assist you in handling all tasks related to your lawn care, and can help you winterize lawn sprinkler systems quickly and easily.