B101.0 Adjusting the Burner Input

The input rate of the burner shall be adjusted to the value in accordance with the appliance manufacturer's instructions. Firing at a rate in excess of the nameplate rating shall be prohibited. The input rate shall be adjusted by changing the size of a fixed orifice, changing the adjustment of an adjustable orifice, or readjusting the appliance's gas pressure regulator outlet pressure (where a regulator is provided in the appliance). [NFPA 54:11.1.1]

Gas input ratings of appliances shall be used for elevations up to 2000 feet (610 m). The input rating of appliances operating at elevations above 2000 feet (610 m), shall be reduced in accordance with one of the following methods:

1. At the rate of 4 percent for each 1000 feet (305 m) above sea level before selecting appropriately sized appliances.
2. As permitted by the Authority Having Jurisdiction.
3. In accordance with the manufacturer's installation instructions. [NFPA 54:11.1.2]