CERTIFIED BACKFLOW TESTINGA backflow protection device is required for all homes and businesses in San Francisco that have a potential hazard such as radiant floor heating and some fire or irrigation systems. A properly working and certified Backflow device is necessary in order to protect the public water supply from private water contamination. Ace Plumbing and Rooter provides you one-stop service when it comes to backflow testing and any necessary repairs. Typically, backflow tests take less than one hour, though your water will have to be shut off for that brief time. Once you pass the test, we will attach a certificate tag from the San Francisco Department of Public Health to document your compliance.