RBI’s FlexCore fire tube boiler with AHRI-rated efficiencies as high as 96.8 percent now includes. The latest evolution of the FlexCore includes sizes up to 7,000, 8,000 and 9,000 MBH. A conical-shaped tube sheet coupled with rounded rectangular fire tubes allows for even heat transfer at all levels of the heat exchanger. Heat exchanger design virtually eliminates the stresses often seen in competitive models with expansion and contraction of the heat exchanger. HeatNet 3.0 with touch screen technology provides a control platform capable of seamlessly integrating FlexCore into any application including variable primary systems. HeatNet Online allows users the ability to change set points and trend boiler plant performance as well as receive live updates to any smart phone.