Navien NFB-399C - 399,000 BTU Condensing Heating Boiler

The Navien NFB-399C is a commercial-grade condensing boiler engineered for maximum efficiency and performance. With an impressive 97.5% thermal efficiency and a 15:1 turndown ratio, it delivers reliable operation across a wide range of heating demands. This model features a patented stainless steel fire tube heat exchanger, an intuitive 7" touchscreen control interface, and flexible venting options. It's approved for high-altitude installations and is compatible with building automation systems through BACnet, Modbus, or LonWorks.

Features:

97.5% thermal efficiency
15:1 turndown ratio
Stainless steel fire tube heat exchanger
7" color touchscreen interface
PVC, CPVC, polypropylene, and stainless venting options
Common venting up to 4 units, cascading up to 32
Built-in pump relays for 3-zone systems
Top and bottom piping connections
Low NOx emissions
Approved for altitudes up to 10,100 ft
Compatible with BAS protocols (Modbus, BACnet, LonWorks)

Applications:

Commercial buildings with high heating demands
Boiler banks requiring cascading and common venting
Energy-efficient system upgrades
Installations requiring top or bottom piping flexibility
Multi-zone hydronic systems
High-altitude commercial environments

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Collection: 200,000+ BTU

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NFB-399C - Condensing Heating Boiler - 399,000 BTU