This First Edition of ANSI/UL 2561 includes requirements that cover 1400°F chimneys. The standard includes, without substantive changes, content from the Standard for Factory-Built Chimneys for Residential Type and Building Heating Appliances, UL 103 and the Standard for Medium Heat Appliance Chimneys, UL 959 which are currently used to evaluate 1400°F chimneys.