Navien’s NPE water heater series expands with the addition of the NPE-150S model. This smaller size “S” standard version with an efficiency of 0.97 EF has a heating capacity of 18,000-120,000 Btu/hr., and will produce 5.3 gpm at 45° temperature rise. It features: 1/2” gas pipe capability, 2” PVC venting up to 60’, dual stainless-steel heat exchangers, an integrated and easy-to-use control, field gas convertibility, cascade capability without an external control and a warranty.