The Navien 30008571A Flow Sensor T701-128R NPE-A is a high-precision component designed for Navien NPE-A series tankless water heaters. It accurately monitors and measures water flow to ensure optimal performance and consistent hot water delivery. By providing precise flow data to the control system, it enhances heating efficiency, prevents overheating. https://www.partshnc.com/30008571a-navien-tankless-water-heaters-flow-sensor-t701-128r-npe-a