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
ZCS
