1. Anything that is above ground or is close to the surface will likely freeze so these steps are important. Most buildings have either an underground stop and waste or irrigation shut offs, make sure these are turned off.
2. Connect air compressor to main line and pressurize. A quick coupler is one of the best connections. A back flow preventer, hose bib, or secondary filter may also be connected to with the right fittings.
3. Turn on each valve from the clock and allow time to blow all the water out of the sprinkler heads.
4. Turn the clock off. This will prevent the controller from activating the solenoids at the valves.
5. Make sure backflow preventer is removed or free of all water. If it can’t be removed Hunter recommends: