There are two main types of fuels that can be used in Napoleon® Fireplaces. They are solids: wood or pellet products, and gas: natural gas or propane. All of our gas fireplace models are approved to burn either natural gas or propane. A conversion kit is available for most models to change from natural gas to propane and vice versa. Fireplaces that are designed to consume a solid fuel such as wood or pellet products cannot be converted to consume a gas such as natural gas or propane.