Navien introduced its new NFC series stainless steel fire tube combi-boilers at AHR Expo in Atlanta. This product will be available in two sizes, NFC-175 (175,000 Btu/h) and NFC-200 (199,900 Btu/h), each offering 95% AFUE, 11:1 turndown ratio, PVC venting up to 150’, high-altitude approval up to 10,100’, and industry-leading residential and commercial warranties, the company explains. The new Navien NFC combi-boiler models come with a patented in-house designed and manufactured heat exchanger, low-profile burner for ease of service, advanced controls offering intuitive user navigation, a built-in DHW module (pump, flat-plate heat exchanger, three-way valve, mixing valve, water-adjustment valve and auto-water fill valve), common venting capability up to 8 units, cascading capability up to 16 units, and built-in hardware to connect up to 3 zone pumps without a need for additional external controllers.