The ESC™ gas boiler is a modern, versatile boiler designed to maximize the comfort and efficiency of nearly any heating system. It delivers the perfect balance of energy-saving performance, durability and features for homes where a chimney-vented boiler is not an option. The ESC™ features an advanced cast iron heat exchanger and a well-insulated heavy-duty steel base. Additionally, The ESC™ features the IQ Control System which not only monitors boiler operation, but also gives the ability to add additional energy saving features to the boiler. By striking a balance between the types of advanced energy saving features typically seen on high-end condensing boilers and the tried-and-true durability of cast iron boilers, the ESC™ is uniquely able to offer homeowners the best of both worlds.