The NFB-C
![Nfb-c](https://navien-production-3.s3-us-west-2.amazonaws.com/2022/05/10/06/29/52/785af3c4-119c-4b36-8c97-52e26b6853c9/NFB-C.png)
![Multiple venting options](https://navien-production-3.s3-us-west-2.amazonaws.com/pictures/1884/aee40252c7bd84c0ee0571c0004200ee57ca5b2a/Multiple_venting_options.png)
Multiple venting options. Low exhaust gas temperatures allow use of PVC, CPVC, polypropylene (rigid and flexible) and stainless-steel venting reducing installation time and costs.
![Heat exchanger 4](https://navien-production-3.s3-us-west-2.amazonaws.com/pictures/1931/45ea02467b30319c3dc631757cca157fea4e0234/Heat_Exchanger_4.png)
Patented stainless steel fire tube heat exchanger Navien’s innovative heat exchanger design is ASME‑Certified,“H” Stamped, and reduces high-stress point weld failures common on other combi-boilers.
![Dual venting and field gas2](https://navien-production-3.s3-us-west-2.amazonaws.com/pictures/1886/fe128d9cab02737cd4e5e253ea2f79e6d857bb49/Dual_venting_and_field_gas2.png)
Dual Venturi and field gas convertibility. Dual Venturi system creates better combustion control and turndown ratio. Orifice for easy field gas convertibility from NG to LP. Conversion kits included.
![Nfb-c](https://navien-production-3.s3-us-west-2.amazonaws.com/2022/05/10/06/29/52/785af3c4-119c-4b36-8c97-52e26b6853c9/NFB-C.png)
![Piping](https://navien-production-3.s3-us-west-2.amazonaws.com/pictures/1930/a67e2f8154edf7566b18d1abaaf1d7e0fa797cdf/piping.png)
Top and bottom piping
Easy pipe connections for floor or wall-hung installations.
![Piping](https://navien-production-3.s3-us-west-2.amazonaws.com/2022/05/10/05/46/08/1e15df68-3e9c-44bb-83c7-d35dea4383c2/piping.png)
Top and bottom piping
Easy pipe connections for floor or wall-hung installations.
![Low gas pressure operation2](https://navien-production-3.s3-us-west-2.amazonaws.com/pictures/1889/d31d58c423a40fd6378cbfda8ba9ddcb4cfc8505/Low_gas_pressure_operation2.png)
Low gas pressure operation. Negative pressure regulating gas valve ensures maximum performance all the way down to 3.5" of water column on natural gas and 8" of water column on propane gas.
![Circuitboard2](https://navien-production-3.s3-us-west-2.amazonaws.com/pictures/1878/456966b587a240809d02a4fcce0a9088b55c3e63/CircuitBoard2.png)
Built-in hardware connects boiler pump & 3 zone pumps. All integrated into the NFB-C circuit board. Also includes a DHW priority zone
![Advanced controls3](https://navien-production-3.s3-us-west-2.amazonaws.com/pictures/1926/b911dd4c7c255b00502900a49435c50ba1b5262f/Advanced_controls3.png)
Advanced 7" touch screen controls Easy intuitive navigation for setup, troubleshooting and operation.Built-in USB port
Download boiler data and settings. Upload software updates and boiler settings.
The NHB
![Nhb](https://navien-production-3.s3-us-west-2.amazonaws.com/2022/04/27/22/13/08/182c57ff-a593-460f-974c-52d2875a5f35/NHB.png)
![A](https://navien-production-3.s3-us-west-2.amazonaws.com/pictures/1871/4e7043bf1908a24252ffeadbe5d6d66175b40127/A.png)
2" venting up to 65';
3” up to 150’ (including schedule 40 PVC).Vent Installation Detector (VID) for added safety.
![Nhb heat exchanger2](https://navien-production-3.s3-us-west-2.amazonaws.com/pictures/1890/fdac74dacd085b567f0931905a1e72a71b9dd288/NHB_Heat_Exchanger2.png)
The condensing technology of the dual stainless steel heat exchangers saves energy, reduces greenhouse gasses.
![Nhb](https://navien-production-3.s3-us-west-2.amazonaws.com/2022/04/27/22/13/08/182c57ff-a593-460f-974c-52d2875a5f35/NHB.png)
![Gas flow control system](https://navien-production-3.s3-us-west-2.amazonaws.com/pictures/1881/b8d169195e738a6ff040336efd79a2af36d7961a/gas_flow_control_system.png)
The sophisticated gas flow control system provides a high turndown ratio which reduces energy waste and excessive boiler cycling.
![Gas flow control system](https://navien-production-3.s3-us-west-2.amazonaws.com/pictures/1881/b8d169195e738a6ff040336efd79a2af36d7961a/gas_flow_control_system.png)
The sophisticated gas flow control system provides a high turndown ratio which reduces energy waste and excessive boiler cycling.
![Control3](https://navien-production-3.s3-us-west-2.amazonaws.com/pictures/1882/e5b958c21932fe1582006e8649469c8a502f9092/Control3.png)
NHB integrated control provides industry-leading options and features including adjustable heat capacity, temp boost for outdoor reset control, adjustable anti-cycle timer and freeze protection.
![Tube](https://navien-production-3.s3-us-west-2.amazonaws.com/pictures/1883/bef8c2d0133f385a30b014fbbd84b37555627e41/Tube.png)
1/2" gas pipe capability up to 24' (subject to local codes). Cuts installation time, no need to install new gas lines for retrofit applications.