Unit heaters shall be installed in accordance with the listing and the manufacturer's instructions. Oil-fired unit heaters shall be tested in accordance with UL 731.
Suspended-type unit heaters shall be supported by elements that are designed and constructed to accommodate the weight and dynamic loads. Hangers and brackets shall be of noncombustible material. Suspendedtype oil-fired unit heaters shall be installed in accordance with NFPA 31.
A unit heater shall not be attached to a warm-air duct system unless listed for such installation.