A Febco DCA may leak for several reasons, including worn check valve seals, debris inside the assembly, freezing damage, or high water pressure. Dirt, sand, or small particles can prevent the internal checks from sealing properly, leading to constant dripping or pressure loss. Leaks can also occur around test cocks, shut-off valves, or union connections due to damaged O-rings or loose fittings. In many cases, a repair kit can restore proper operation. Annual backflow testing and regular maintenance help identify problems early and prevent more serious damage.