VARIABLE-SPEED TWO-STAGE GAS FURNACE—95% AFUE Higher AFUE equals greater energy savings. This 95% AFUE variable-speed two-stage Atlas Butler gas furnace saves energy while delivering consistent heat and overall comfort. Click for Details...

VARIABLE-SPEED TWO-STAGE GAS FURNACE—80% AFUE Unlike single-stage furnaces—which heat up fast and shut down fast, going from too hot to too cold—This Atlas Butler gas furnace delivers consistent heat and overall comfort. Click for Details...

TWO-STAGE GAS FURNACE—80% AFUE In a two-stage system, the furnace automatically adjusts to the temperature, normally operating at a quieter, primary stage and modulating to boost heat as the temperature drops. Click for Details...

ONE-STAGE GAS FURNACE—95% AFUE Higher AFUE equals greater energy savings. This 95% AFUE Atlas Butler gas furnace saves energy and has been designed to run quietly and efficiently. Click for Details...