About The Boiler; Description Of The Boiler; Parts Of The Boiler - Navien NFB-175H User's Information Manual

2. About the Boiler

2.1 Description of the Boiler

The Navien NFB-H boiler is available in 2 models:
NFB-175H and NFB-200H.
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 combustion controls.
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.
6 About the Boiler

2.2 Parts of the Boiler

2.2.1 Front View
Combustion
Air Intake
2.2.2 Bottom View
A
3.2" (81.7 mm) 9.6" (244 mm)
14.6" (370 mm)
# Description
A Heating Supply
B Heating Return
C Gas Connection
D Condensate Outlet
Exhaust
Gas Vent
B C D