About The Boiler; Description Of The Boiler; Parts Of The Boiler - Navien NFB-301C User's Information Manual

2. About the Boiler

2.1 Description of the Boiler

The Navien NFB boiler is available in 2 models: NFB-301C, and
NFB-399C.
The main features are as follows:
Power Interruption: When the power is restored after a power
failure, the boiler will automatically start and return to normal
operation. A manual reset is not required.
Freeze Protection: A sensor inside the boiler automatically
detects the temperature and, if necessary, initiates a safety
heating cycle to prevent internal equipment damage due to
freezing temperatures.
Short-Circuit Protection: Any short-circuit occurring in the
boiler's electrical circuit immediately blows the internal glass
fuses and automatically cuts off the gas supply.
Lightning Protection: Each boiler is specially grounded, both
internally and externally, to protect against lightning strikes.
Carbon Monoxide Protection: The boiler is designed to maintain
a safe air-to-gas ratio and combustion rate. This function is
continuously monitored by the boiler's air ratio control module.
Auto Fan Detection: The rotation of the fan is automatically
detected and controlled. Fan failure will stop the operation of
the boiler.
Boiling Prevention: Excessive temperatures will automatically
stop the boiler.

2.2 Parts of the Boiler

2.2.1 Front View
Combustion
Air Intake
2.2.2 Bottom View
A
# Description
A Heating Supply
B Condensate Outlet
C Heating Return
D Gas Connection
Exhaust
Gas Vent
B C D
About the Boiler 5