Backflow preventers typically fail due to internal mechanical wear, environmental stressors, or neglect in maintenance. Assemblies rely on precise pressure differentials to maintain a seal, even minor internal issues can lead to failure.
The most common reasons for failure include the following:
Internal Wear and Tear: rubber seals, gaskets, and o-rings naturally degrade, crack, or become brittle over time, and springs that operate the check valves weaken or snap, preventing the valves from closing completely.
Debris and Mineral Buildup: small particles like sand, rust, or rocks from the water supply can become lodged in the check valves, preventing a watertight seal. Hard water can also lead to limescale that interferes with moving parts.
Freezing Temperatures: water trapped inside the device expands when it freezes, which can crack the internal plastic components or the main metal housing.
Pressure Spikes: Sudden surges in water pressure—often caused by rapid valve closures—can shock and damage delicate internal components or blow out seals.
Most jurisdictions require annual testing by a certified professional, as backflow preventers often show no visible signs of internal failure until they are formally inspected.
Chicago Backflow has been installing, maintaining, and repairing backflow devices in Illinois and Indiana for generations! Learn more at chicagobackflow.com.
