CREST Boilers are designed with a top-mounted micro-metal fiber burner, engineered specifically for fire-tube technology. The Wave fire-tube configuration creates turbulence as flue gas products flow down the tube, scrubbing the energy. As water flows up the vessel, super-heated flue products flow down the fire tubes. With one pass, heat is transferred and flue gases reach condensing temperatures. With an 8-in. touchscreen and multi-color interface, the SMART TOUCH operating system provides control and easy-to-use monitoring functions. The SMART TOUCH control can be integrated directly into a building automation system through BACnet, ModBus, and other communication protocols using a gateway device. Cascade sequencing can be programmed for lead-lag or efficiency optimized operation. Fire-tube technology also allows CREST boilers to operate over a wide range of flow rates with very low pressure drop, allowing for a full flow system.