By order of the publisher, historical UL documents are not returnable for any reason. Once you place an order for an historical document, we cannot issue a refund, credit, or exchange of any kind.

These requirements apply to the following gas fuel-burning heating appliances:

1. Direct-vent system appliances for manufactured homes and recreational vehicles; and
2. Vented appliances for manufactured homes other than the direct-vent system type that provide for separation of the combustion system from the atmosphere of the manufactured home by an installatio n method.

Requirements for the installation and use of heating applian ces in manufactured homes and recreational vehicles are included in:

1. The Department of Housing and Urban Development Manufactured Home Construction and Safet y Standards, Chapter II of 24 CFR, Part 3280-1994; and
2. The Standard for Recreational Vehicles, NFPA 501C-1993.

An appliance designed to burn eit her oil or gas, and a gas appliance designed to be converted to burn oil by the installation of an optional factory-furnish ed burner, shall also comply with the requirements in the Standard for Liquid Fuel-Burning Heating Appliances for Manufactured Homes and Recreational Vehicles, UL 307A.

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