The new Navien NPE Series premium gas condensing tankless water heater reduces time and labor for a typical tankless retrofit by utilizing existing gas lines and existing flue chases. Features include: 2” PVC venting up to 60’ or a System 636 (ULCS636) option for Canada; 1/2" gas lines up to 24’; ComfortFlow and intelligent preheating technology; buffer tank and recirculation pump included; field convertability from natural gas to liquid propane gas; cascading-capable; and dual stainless-steel heat