2. About the Boiler
2.1 Description of the Boiler
The Navien NFC-H boiler is available in 2 models:
NFC-250/175H and NFC-250/200H.
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.
2.2 Parts of the Boiler
2.2.1 Front View
Combustion
Air Intake
2.2.2 Bottom View
A
B
2"
3.4"
3.3"
(53 mm)
(87 mm)
(85 mm)
14.6" (370 mm)
#
Description
A
Heating Supply
B
Hot Water Outlet (DHW)
C
Cold Water Inlet (DHW)
D
Auto Feeder Inlet (Make-up Water)
E
Heating Return
F
Gas Connection
G
Condensate Outlet
Exhaust
Gas Vent
C
D E
F G
5.4"
5.4"
(136.6 mm)
(136.6 mm)
About the Boiler
7