The Clean Energy Heating Systems CE-340 Waste Oil Boiler allows for the creation of free hot water for radiant heat or other purposes by burning waste oil. The boiler features durable steel components, large-diameter flue tubes and a patented Clean Energy burner that turns used petroleum products into free heat. And as a high-mass/high-volume boiler system, it maintains a more consistent water temperature and more efficiently retains heat than other popular boilers. Its front and back doors open easily for straight-through cleaning, while large, straight-through flue tubes reduce ash buildup and allow for a longer interval between cleanings.