Generac manufactures the Guardian Series Home Standby Generators to run on either Natural Gas (NG) or Liquid Petroleum Gas (LPG) which is also called propane. While running on Natural Gas, the generator produces a maximum continuous output of 19,500 watts at 120/240 Volts, 81.3 Amperes. On propane (LPG) the maximum continuous capacity is 22,000 watts at 120/240 Volts, 91.6 Amperes.
Natural Gas has a lower BTU content than LP Gas which accounts for the lower output capacity. Regardless of the fuel used, the 7043 requires a minimum of 1000 BTUs per cubic foot.
Generac configures the Guardian 7043 at the factory to run on Natural Gas, but it quickly converts to LP Gas during installation. A Fuel Conversion Knob located above the fuel mixture rotates 180 degrees to change the unit from NG to LP, or from LP to NG. When switching to LP, Generac recommends a minimum tank size of 250 gallons to maintain adequate fuel pressure and volume.