Navien expands its premium condensing tankless NPE water heater series 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/H and will produce 5.3 GPM at a 45 F temperature rise. The NPE-150S features 1/2-inch gas pipe capability, 2-inch PVC venting up to 60 feet, dual stainless steel heat exchangers, an integrated and easy to use control, field gas convertibility and cascade capability without an external control.