A value-priced, high efficiency condensing boiler that is simple enough to install quickly AND offers valuable extras not found on competitive models. U.S. Boiler Company has delivered. The K2 offers a comprehensive feature list, unequalled ease of setup, maintenance, and operation in a package that costs far less than you’d expect for the impressive value that’s built in. And best of all, it’s built and tested with pride in Lancaster, Pennsylvania by U.S. Boiler Company. Furthermore, with the new, advanced Sage2.3™ Control System, the K2 condensing boiler now offers 10:1 turndown and impressive gains in efficiency. The K2 is now 95% AFUE for all sizes! The K2 condensing boiler’s simplified design includes a hinged inner door that isolates electronics and controls from combustion and waterside components, making for fast, clutter-free service access. Venting the K2 is simple as well, regardless of whether one pipe, two pipe, horizontal or vertical configurations are needed.