U.S. Boiler Co. expanded its Alta line of condensing, gas-adaptive boilers with a larger combi size and several heat-only models. The stainless steel Alta Combi boiler is now available in 200 MBH DHW input (5.2 gpm / 150 MBH heating input). In addition, Alta heat-only models are available in 120, 150 and 180 MBH. At 95% AFUE, Alta boilers feature next-generation gas adaptive technology that provides the shortest installation time and lowest operating costs, the company says.