2. About the Boiler
2.1 Description of the Boiler
The Navien NCB boiler is available in 3 models: NCB-180, NCB-210,
and NCB-240.
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.
Automatic Water Fill: Should the water level in the system fall too
●
low, a sensor will automatically activate the refill circuit.
Freeze Protection: A sensor inside the boiler automatically
●
detects the temperature and, if necessary, initiate 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.
Thermostat Control Failure: Should the thermostat fail to
●
function properly, the boiler's gas supply will be shut off
automatically as a safeguard.
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
Front View
Combustion
Air Intake
Bottom View
a
b
c
d
e
#
Description
a
Pump Drain Plug
b
Space Heating Strainer
c
Space Heating Supply Connection
d
Space Heating Return Connection
e
DHW Hot Water Outlet Connection
f
Gas Connection
g
Cold Water Inlet Filter
h
Condensate Water Outlet
i
Auto Feeder Connection
j
Cold Water Inlet Connection
Exhaust
Gas Vent
f
g
h
i
j