Forgive me if I'm wrong, but you stated you had this furnace installed and the question you asked sure makes it look as though you are installing it. Site rules forbid us from giving out installation/service procedures to non-professionals. Read the installation instructions and you should get your answer.
A Veteran is a person, who at some point in their life, wrote a blank check payable to the United States of America for payment up to and including their life.
Gene Castagnetti-Director of the National Memorial Cemetery of the Pacific in Hawaii