Introducing A801X – Ameristar’s new, 80% AFUE gas furnace family. With great new features such as a 34” cabinet height, 4-way multipoise design, and BTU/h options down to 26,000, this family will be a great fit in many applications. For more details regarding model offerings and dimensions, please refer to the chart shown in the Product Bulletin below. All of our A801X models are offered in a California, 40 ng/J version, indicated by a “T” in the 12th digit. Note: The Ameristar model family M801P will cease production on July 2, 2019.