86% Efficiency


Oil, Steam
3-Pass Cast Iron Heat Exchanger

The Most Efficient Cast-Iron Steam Boiler in the World!

The MegaSteam is a U.S. Boiler exclusive. Designed specifically as a residential oil-fired steam boiler, the MegaSteam achieves 86% AFUE efficiency with a 3-pass cast iron heat exchanger – the only one of its kind in the world. Its unique design makes it highly corrosion resistant, a fact that U.S. Boiler Company backs up by giving the MegaSteam the best warranty in its class. Not only does the MegaSteam have a 10-year warranty on the heat exchanger, it has the industrys only 5-year warranty on water side corrosion. The MegaSteam is available fully packaged with 3 inches of insulation, a deluxe powder-coated steel jacket and brand name components from industry leading companies. Unmatched in the industry!

  • Oil-fired boiler
  • For steam applications only
  • Unique 3-pass heat exchanger for exceptional efficiency and steam quality
  • Unsurpassed 5-year Warranty against water side corrosion
  • Tankless coils are available
  • 10-year Limited Warranty on the heat exchanger
  • Optional 5 or 10-year parts & limited labor warranty
  • Extended Boiler Warranty Plans are administered by CornerStone United, Inc.