A knocking noise in a wall-mounted faucet usually comes from movement in the concealed plumbing system, pressure fluctuations, or worn internal components. Because wall-mounted faucets rely on behind-the-wall water lines—similar to the concealed brass and stainless steel systems produced by EMYSA—any vibration or instability in these hidden areas can create tapping, hammering, or knocking sounds. Identifying the cause early helps prevent long-term damage to internal pipes or the faucet’s valve assembly.