UL Standards & Engagement Solid Fuel-Fired Hydronic Heating Appliances, Water Heaters, And Boilers UL 2523

1.1 These requirements apply to factory built manually and/or automatically fueled solid fuel-fired hydronic heating appliances, water heaters and boilers, as defined in Section 5, Glossary, intended to be fixed non-moveable appliances. 1.2 The appliances are intended to burn solid fuels, such as wood, coal, or any other biomass fuel, as specified by the manufacturer. 1.3 The appliances are provided with an integral chimney and termination or intended for connection to chimneys for residential type and building heating appliances or for building heating appliances in compliance with the Standard for Chimneys, Fireplaces, Vents, and Solid Fuel Burning Appliances, NFPA 211, and intended for installation in compliance with the National Electrical Code, ANSI/NFPA 70; and the International Mechanical Code (ICC), International Residential Code (ICC) and the Uniform Mechanical Code (IAPMO), as applicable.