Navien’s NPE-2 series condensing tankless water heaters feature an EZNav upgraded advanced multi-line control panel with Setup Wizard, high efficiency up to 0.96 UEF, 2” PVC venting up to 75’, cascade capability up to 32 units and common vent capability up to 12 units. Like the original NPE, NPE-2 continues to offer dual stainless-steel heat exchangers and patented ComfortFlow recirculation system with built-in pump and buffer tank on the NPE-A2.