Navien Inc. has started shipping its new lines of fire tube boilers and combi-boilers. The NFB-H condensing fire tube boilers and NFC-H condensing fire tube combi-boilers were first introduced by Navien during the company's Boiler Virtual Launch Event on Feb.16.

Navien’s upgraded NFB-H high-output condensing fire tube boilers are available in two sizes, NFB-175H and NFB-200H. Both models include Navien’s patented stainless steel fire tube heat exchanger with a non-metallic condensate drain pan. The combustion chamber is form pressed to resist corrosion and the heat exchanger is robotic laser welded to ensure the highest quality with repeated results. New high-efficiency features on the NFB-H include turndown ratios up to 15:1, powered connections for 3 zone pumps or 3 zone reduce areas valves, easy to use Setup Wizard for improved installation, 2-inch venting up to 65 inches and 3-inch venting up to 150 feet.

NFC-H high-output condensing fire tube combi-boilers are also available in two models, NFC-250/175H and NFC-250/200H. The NFC-H also offers Navien’s patented stainless steel fire tube heat exchanger along with a built-in DHW module that includes a flat plate heat exchanger. New advanced features on the NFC-H include turndown ratios up to 15:1, powered connections for 3 zone pumps or 3 zone valves, easy to use Setup Wizard for improved installation, 2-inch venting up to 65 feet and 3-inch venting up to 150 feet. The NFC-H also includes increased DHW performance with up to 210,000 BTU/H for DHW, offering up to 5.4 GPM at a 70-degree temperature rise.