Backflow Preventer

How to Drain Your Backflow Preventer

The backflow preventer is the plumbing device attached to the outside wall of the house and is the source of water to the irrigation system. Because this unit and the copper piping attached to it are exposed to the air, this unit can freeze and burst in only a few hours of below freezing temperatures. During the spring and fall, outside temperatures can often dip below freezing during the night. If you see forecast temperatures below 32 degrees, it is important to follow the draining procedure below to prevent costly damage to your system.

  1. Turn off main shut-off valve to the system (A), typically in your basement.
  2. Remove or open the drain plug (E) on the piping outside.
  3. Turn valves (C) & (D) and test cocks to a 45 degree angle (half open-half closed) position.

This procedure will protect your backflow preventer during freezing temperatures either before we winterize your system in the fall or after we start up your system in the spring. Also, follow this same procedure to prepare for your system fall winterizing if you choose not to be at home at the time of this service. Simply leave access to the System Controller and we can take care of the winterizing without the need to enter your home.


Minnesota Contractors License #20148423

Technology Systems Contractors License # TS-00404

Construction Bonding Company: Rudnik Surety