The Inferno Fierce GAS Boiler Boiler was designed with almost 30% more cast iron then any other competitive boiler in its class. It consists of extra deep 2 ¾" sections which increase the boiler’s water content and its total water surface. The new design features, aid in the heat transfer and heat retention, and increase the efficiency rate to over 84%. All of the components are built within the Inferno Fierce GAS Boiler. The boiler was built to make the service of the boiler as easy as possible. This particular boiler is also designed to be vented through an outside wall, making it easy to convert electrically heated buildings that have no chimney. However, it can still be vented with your typical gas water heater into the traditional masonry chimney.