International Comfort Products Corporation, or ICP, a subsidiary of United Technologies Corporation, manufactures Heil air conditioners. ICP acquired Heil in 1986, and Carrier Corporation subsequently acquired ICP in 1999. As of 2015, United Technologies Corporation owns Carrier.
Heil's current line of air conditioners include many sold under the Observer brand name. Heil's selection includes air conditioners with a variety of seasonal energy efficiency ratios, models with two-stage cooling, horizontal units, ductless mini-splits, fan coils and modular blowers. As of 2015, Heil customers can register a product online via an interface provided by ICP. Heil also offers a no-hassle replacement limited warranty with coverage periods ranging from one to 10 years.