Lochinvar’s KNIGHT® wall mount fire tube boiler ranges from 55,000 to 399,999 Btuh. Select models provide up to 10:1 turndown, top and bottom water connections, and an upgraded SMART SYSTEM Control®. The refined KNIGHT wall mount fire tube boiler models WHN56-286 offer 95% AFUE while the WHN400 is rated with 94.4% Thermal Efficiency, Low-NOx emissions and a fully modulating burner. The newest version of the SMART SYSTEM control is standard on all WHN wall mount fire tube models and offers an even larger multi-color graphic LCD display. The SMART SYSTEM interface features setup and navigation of parameters. In addition, the SMART SYSTEM now offers DHW recirculation pump control, LOCH-N-LINK® programming, cascade leader redundancy, and modulation factor.