Water expands as it freezes, so don’t forget to winterize your irrigation system by closing the water supply and removing all the water in the underground pipes! You can have a professional do it for a fee, or you can do it yourself for the cost of a rented compressor, either way you should understand the process.
- We recommend using a 10-cfm air compressor with hose. If you have a smaller compressor, consider renting one from a local tool rental place such as Rousch Hardware, or from the Tool Library.
- Close off the two valves to the backflow preventer. You don’t want to damage this valve, as it needs to pass inspection and keeps the municipal or county water supply safe.
- Connect your compressor to the sprinkler system by removing the plug on the blow-out port. Use a quick-connect adapter to connect your system to the compressor.
- Set the compressor to no more than 80 PSI for rigid PVC (white) or 50 PSI for flexible polyethylene (black) pipe.
- Turn off the water supply.
- Set the system timer to open a single zone and open the manual drain on the end of that zone if your system has one.
- Have a partner at that zone, watching the sprinkler heads. They should notify you as soon as no more water is coming out.
- Turn on the compressor and blow out that zone. The sprinkler head should pop up and sprinkle, stopping when the water is gone. Disconnect as soon as the zone runs dry, as plastic parts can melt inside the system without the water to keep them cool.
- Move on to the next zone, opening only one zone at a time and blowing it out.
- When you are done blowing out all the zones, repeat one more time to get any water that collected.
Properly prepared for cold weather, these automated watering systems will last for many years with few repairs. So don’t forget to winterize your irrigation system by blowing out the water and preventing damage from freezing water.