Auer Steel & Heating Supply Co. 3050 Progress Rd Madison WI 53716 was founded in Milwaukee by Don Curtes Sr. in 1940. They are a full-service supply house of high quality indoor comfort products including furnaces air conditioners humidifiers air cleaners heat and energy recovery ventilators controls and other heating and air conditioning accessories. Areas Served: Auer Steel & Heating Supply Co. has locations across the upper Midwest. What Brands Does Auer Steel Sell? Auer Steel & Heating Supply Co. offers brand names such as Bryant Carrier Fantech First Company Grundfos Honeywell Mitsubishi Panasonic Reznor Taco Unico and many others.