High-capacity, high-efficiency commercial heating

The NFB700-C Series is Navien’s first floor-standing condensing fire tube boiler, built for demanding commercial applications. With capacities from 500 to 1,000 MBH and turndown ratios up to 15:1, these boilers deliver reliable, efficient heating in a compact footprint.

By combining Navien’s innovative fire tube design with a floor-standing format, the NFB700-C delivers the high input capacity, efficiency, and certifications specified for large commercial boilers, providing engineers with a reliable solution built to the highest standards.

Low operating costs with an industry-standard thermal efficiency rating of 97.5%.

Advanced gas control system reduces energy waste and excessive boiler cycling.

Advanced stainless steel
fire tube heat exchanger.

Smart controls with 10.1" color touch display with built-in Wi-Fi connectivity.

NG to LP field convertible and dual Venturi for consistent air-to-gas ratio.

Capable of cascading
up to 8 boilers.

Proven controls and technology in boiler capacity up to 1 million BTU/h.

Low NOx at less than 20ppm.

Tankless reverse osmosis system installed beneath kitchen sink with dedicated faucet

Proven stainless steel fire tube heat exchanger

At the core of every NFB700-C is Navien’s patented stainless steel fire tube heat exchanger, engineered for strength, durability, and thermal performance.

97.5% thermal efficiency for lower operating costs
160 PSI maximum allowable working pressure for diverse system requirements
ASME H-stamped; CSA, AHRI & SCAQMD certified for safety, efficiency, and low NOx compliance
High-altitude certification up to 10,100 ft
Included insulation on the heat exchanger exterior to reduce thermal losses and improve efficiency

Smarter commercial boiler 10.1" touchscreen control panel with intuitive setup software

The NFB700-C is engineered with advanced onboard intelligence to simplify installation, optimize temperature control, and streamline daily operation, making it ideal for complex institutional heating systems.

Navien Startup Wizard makes navigating through the setup operations and troubleshooting simple.
Set your language, date, time, and temperature easily with a tap on the screen.
Customize your system with zone or pump settings, outdoor reset/curves, outdoor high/low temperature and WWSD functions.

Security passwords, WiFi mobile app, and QR code for registration are all built into the system.
The extensive clear text service feedback also helps troubleshoot most issues.

Flexible installation & cascade capability

Whether replacing aging boilers or installing new systems, the NFB700-C is designed for fast, straightforward setup.

Cascade up to 8 units for redundancy and capacity (with sequencing to balance run hours)
Common venting for up to 4 units to reduce penetrations and simplify venting
Venting lengths up to 150 ft using PVC, CPVC, polypropylene, or stainless steel
Compact footprint with front, side & top access for easier service in tight rooms
Standardized connections for vent, gas, and water lines
Conversion kits included — each unit ships with a propane conversion kit, high-elevation kit, and installation components

The Navien cascade technology provides both preset and customizable system control. This allows setup to optimize the heating demand staging, while enhancing the energy savings.

Built-in safety

The NFB700-C is engineered with multiple layers of protection for enhanced operation safety in demanding commercial environments.

Together, NFB700-C features help prevent against common failure points, reduce downtime, and support compliance with commercial safety codes.

Navien NWP500 electric heat pump water heater detail view of internal components

Low water cut-off (LWCO) sensor to prevent overheating when water levels are low
Flame rod and ignition operation detector for reliable combustion monitoring
High-limit sensors for water and exhaust temperature