The Inferno H.E. Boiler is available in Propane or Natural Gas. All the connections on the boiler are located for easy access, which assists in the installation process. All components and wires are marked for easy maintenance and service. This series comes with several mounting configurations saving time and floor space. The H.E. Boiler also vents with any conventional plastic piping. This particular boiler has a special combustion system that will modulate the burner to the exact size required. The electronic combustion system reduces the amount of gas that is injected into the burner, ensuring proper combustion throughout modulation. The air is also drawn from outside, which eliminates the need for fresh air intake into the room, which will decrease heating costs.