Navien NPE-180A Installation Manual

Also see for NPE-180A: Installation manual Installation & operation manual Specification sheet Installation manual Service manual

Navien NPE-180A Installation Manual Manual pdf 37 page image

36 Installing a Cascading SystemWhen installing a cascading system, carefully consider the design of the system and the features of the installation location. Follow all localcodes and regulations, as well as all guidelines for installing the water heater. The following sections describe additional considerations thatare specific to installing cascading systems. Read them carefully before designing or installing the system.4.1 Connecting Water SuppliesSeveral options are available for plumbing a cascading system of water heaters. The options shown here are only examples. The setup youchoose will vary based on the installation location, local building codes, and other factors. Follow all applicable regulations when installing acascading system.You can connect up to 16 water heaters to meet high-volume hot water demands. Some possible connection options include the following: Recirculation via Internal Pumps (“A” model only):CommunicationCableDHW Supply LineRecirculation LineCold Water Supply LineGas Supply LineUnionBall ValveCheck ValveFaucetExpansion TankPressure Relief Valve[NPE-180A/ 210A/ 240A]Note The recommended minimum recirculation flow rate for each water heater is 2 GPM. Depending on the number of water heatersand the diameter of the recirculation line, it may not be necessary to connect all water heaters to the recirculation line. If this isthe case, set the unconnected water heaters to internal recirculation mode. The master water heater must always be connectedto the recirculation line and set to external recirculation mode. Multiple NPE-S Units:CommunicationCableDHW Supply Line Cold Water Supply LineGas Supply LineUnionBall ValveCheck ValveFaucetExpansion TankPressure Relief Valve[NPE-180S/ 210S/ 240S]4. Installing a Cascading System