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 distributor 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.