1.1 These requirements cover oil-fired central furnaces which include forced-air furnaces of the downflow, horizontal, and upflow types. Floor-mounted unit heaters designed to supply heated air through ducts are covered also by these requirements.

1.2 These requirements cover furnaces intended to burn standard grade fuel oils as specified in the Specifications for Fuel Oils, ASTM D396, any biodiesel as defined by the Standard Specification for Biodiesel Fuel Blend Stock (B100) for Middle Distillate Fuels, ASTM D6751, or any fuel oil/biodiesel blend..

1.3 The oil-burning equipment covered by these requirements are intended for installation in accordance with the National Fire Protection Association Standard for Installation of Oil-Burning Equipment, NFPA 31, the International Mechanical Code and the Uniform Mechanical Code.