7
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:
Ɣ
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.
Ɣ
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.
Ɣ
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.
Ɣ
Lightning Protection: Each boiler is specially
grounded, both internally and externally, to
protect against lightning strikes.
Ɣ
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.
Ɣ
Auto Fan Detection: The rotation of the fan is
automatically detected and controlled. Fan failure
will stop the operation of the boiler.
Ɣ
Boiling Prevention: Excessive temperatures will
automatically stop the boiler.
2.2 Parts of the Boiler
2.2.1 Front View
Exhaust
Gas Vent
Combustion
Air Intake
2.2.2 Bottom View
14.6” (370 mm)
2.6” (67 mm)
9.7” (247 mm)
5.2” (131 mm)
A
D E
17.3”
(440 mm)
8.5” (215 mm)
10.6“ (269 mm)
3.3”
(85 mm)
2”
(53 mm)
B
C
F
G
5.4”
(136.6 mm)
5.4”
(136.6 mm)
3.4”
(87 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
2. About the Boiler
Summary of Contents for NFC-250/175H
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