Although backflow preventers are more common at commercial buildings that have fire sprinkler systems, residential customers may need one, too, depending on local regulations.

Irrigation valve in the 'off' position. STEP 2: Once the water is shut off, drain the water out of your backflow preventer. This process is different with different systems.

STEP 2 Once the water is shut off, drain the water out of your backflow preventer. This process is different with different systems.

You don’t want your pipes or the backflow preventers to freeze over. Broken backflow preventers and cracked manifolds could cost between 400 and 600 dollars in repairs. Another thing to be aware ...

To see if you have a backflow preventer on your irrigation system, look for an in-ground rectangle box with a green cover — they’re by the water meter or perimeter of the house.

Installing a backflow prevention valve can be costly. “To install one if you don’t have one already, it can range from $300 to $700 plus,” said Alex Jones, owner of Jones Sprinkler.