The new NFB-175 and NFB-200 high-efficiency condensing fire-tube boilers from Navien are in-house designed and manufactured with Navien parts. The patented stainless steel heat exchanger with a one-piece combustion chamber eliminates high-stress point welds that are prone to corrosion. It is rated AFUE 95 percent and has advanced user-interface controls with intuitive text display and a click wheel simplifies boiler setup. It has built-in hardware to connect a boiler pump, three zone pumps or three zone valves integrated into the unit, so there’s no need to add extra zone panels. 800-519-8794; www.navieninc.com.