UL 391 PDF

Standard for Solid-Fuel and Combination-Fuel Central and Supplementary Furnaces

UL 391 – Standard for Solid-Fuel and Combination-Fuel Central and Supplementary Furnaces

Please note:All interim revisions for this edition available at time of your purchase will be included.

These requirements apply to manually fueled, solid-fuel-fired central furnaces. Included are supplementary central furnaces intended for interconnection withforced-air central furnaces utilizing other fuels, and combination oil-fired and solid-fuel-fired, forced-air central furnaces.

The furnaces are intended to burn solid fuels, such as wood, coal, or any other biomass fuel, as specified by the manufacturer.

The furnaces are intended for connection to chimneys for residential and 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 Standard for Installation of Warm Air Heating and AirConditioning Systems, NFPA 90B; and the National Electrical Code, ANSI/NFPA 70; and applicable mechanical codes such as the BOCA National MechanicalCode, the Standard Mechanical Code, and the Uniform Mechanical Code.

A product that contains features, characteristics, components, materials, or systems new or different from those in use when the Standard was developed, and thatinvolves a risk of fire, electric shock, or injury to persons, shall be evaluated using the appropriate additional component and end-product requirements as determinednecessary to maintain the level of safety for the user of the product as originally anticipated by the intent of this Standard.