Winterize Sprinkler System Method #1: Manual Drain Method
This is used when manual valves are located at the end and low points of the irrigation piping.
1. Shut off irrigation water supply
located in the basement. This will either be a gate/globe valve, ball
valve or stop and waste valve.
2. Open all the manual drain valves.
3. After water has been drained from
the mainline, open the boiler drain valve OR the drain cap on the stop
and waste valve. This will drain the water that is left from the shut
off valve to the backflow device.
4. Open test cocks on backflow device.
5. If sprinkler has a check valve, pull up on the sprinkler to allow water to drain out of the bottom of the sprinkler.
6. Be sure to drain all the water from the backflow, piping and sprinklers.
7. Close manual drain valves.
Winterize Sprinkler System Method #2: Automatic Drain Method
This is used when drain valves are located at the end and low points
of the irrigation piping. They will automatically open and drain water
when the pressure in the piping is less than 10 PSI.
1. Activate valves by shutting off the irrigation water supply found in the basement.
2. Activate a station to relieve the system pressure.
3. After water has been drained from the mainline, open boiler drain valve or drain cap, depending on the type of shut of valve.
4. Drain remaining water between irrigation water shut off valve and the backflow device.
5. Open test cocks on backflow device.
6. Pull up on sprinklers to drain if they have check valves.
7. Be sure to drain all the water from the backflow, piping and sprinklers.
Winterize Sprinkler System Method #3: Blow-Out Method
Consider hiring a qualified licensed contractor to winterize a
sprinkler system with this method. This method uses an air compressor
with a Cubic Foot per Minute (CFM) rating of 125 to 185 for any mainline
of 2” or less and a PSI of 50 to 80. You can rent a compressor.
1. Attach the compressor to the mainline with a quick coupler or hose bib located before the backflow device.
2. Open the test cocks on the vacuum breaker.
3. Shut off the irrigation water supply.
4. Open the drain on the supply line.
5. Once line is drained, close the drain.
6. Connect the air line.
7. Attach the air compressor hose to the fitting.
8. Activate the station on the controller of the sprinklers in the highest in elevation and furthest from the compressor.
9. Do not close the backflow isolation or test cock valves.
10. Slowly open the valve on the compressor to gradually allow air to enter into the irrigation system.
11. Air pressure should be a constant 50 PSI.
12. If sprinkler heads do not pop up and seal, increase the air until they do.
13. Air pressure should NOT EVER go over 80 PSI.
14. Activate each station from the furthest station from the compressor and slowly work your way to the compressor.
15. Activate each station until you do
not see water exiting from the heads. This will take around two to
four minutes per station.
16. Once station is dry, do not continue blowing out air as this can cause friction, which will create heat damage.
17. Shut down the air compressor and release air pressure.
18. Disconnect the air line.
19. If backflow device has a ball valve, open and close the isolation valves on the backflow device several times.
20. Leave isolation valves open at a 45 degree angle.
21. Leave the test cocks open.
Remember, it is recommended that you hire someone to do professionally winterize a sprinkler system with this method.