The Navien 30009437A Cold Inlet Pipe Assembly is a replacement plumbing component designed for compatible Navien NPE tankless water heaters. It connects the incoming cold-water supply to the heater, directing water into the internal heat exchanger for efficient on-demand heating. This assembly supports proper water flow and reliable system operation, helping maintain consistent hot-wa... https://www.partshnc.com/navien-tankless-water-heaters-30009437a-cold-inlet-pipe-assembly-npe