The NAVIEN Tankless Water Heaters 30002282E Water Heater Check Valve is a replacement flow-control component designed for compatible Navien water heating systems. It allows water to move in the intended direction while preventing reverse flow within the system. This one-way operation helps maintain proper water circulation and protects connected components from unwanted backflow. Used... https://www.partshnc.com/30002282e-navien-tankless-water-heaters-check-valve