The MGC Series 3 is available in two sizes from 262 MBH to 299 MBH and is designed for chimney vent applications. With an AFUE of 84.0%, the latest design features a Hydrolevel FuelSmart control that monitors water temperature and delays burner start until residual heat has been transferred to the system for maximum efficiency. An integral Draft Hood and Automatic Vent Damper reduce the overall height and footprint of the boiler, making it ideal for low-clearance/space limited installations.