Navien NFC-200 Quick Installation Manual page 2

Gas Piping Connections

The gas meter capacity
must be greater than
the total gas capacity of
connected appliances.
Gas
Regulator
Gas supply
Gas Inlet Adapter
Bottom View
Water Piping Connections

Space Heating System
A pressure relief valve must be installed when installing piping for a heating system.
3
Install the included / in, maximum 30 psi pressure relief valve on the space heating supply.
4
An ASME approved HV pressure relief valve for space heating system is supplied with the boiler.
You may install the pressure relief valve on the space heating supply of the Navien Manifold System, or on the top connection along
with the air vent (and an external LWCO, if required).
CAUTION
Do not solder piping directly onto the water connections, as the heat may cause damage to internal components. Use
threaded water connections only.
System Fill Connection
Pressure Relief Valve
Air Vent
Air Vent
Bushing
PRV-Air Vent
1
Adapter
2
Clip
Condensate Drain Connection

A condensate drain pipe must be connected to the
bottom of the unit and water must be poured into the exhaust connection to fill the
condensate trap.
Gas Supply Line
The boiler is
recommended
to be the first
appliance to be
connected to
the gas supply
line.
Drip Rig
The Navien NFC boilers have a top connection for an air
vent. An air vent must be installed to purge air from the
boiler system.
Air Vent
To insecure the adapter to the fitting, install the
Pressure
provided clip after inserting the PRV-air vent adapter
Relief Valve External
into the connection on top of the unit.
LWCO
When installing the air vent, install the air vent bushing
between the air vent and the top connection.
Before filling the boiler, remove the air vent cap to allow
the system to fill properly. Replace the cap when the
system is full.
Prior to connecting piping to the boiler, flush
Note
the entire system to ensure it is free of
sediment, flux, scale, debris or other
impurities that may be harmful to the system
and boiler. During the assembly of the
heating system, it is important to keep the
inside of the piping free of any debris
including construction dust, copper burr,
sand and dirt.
Ensure that the vent cap is re-installed and
Note
the vent screws on the system and boiler
pumps are properly tightened before testing
or operating the system.
1
/ " condensate trap fitting at the
2
Condensate trap
Water
Floor drain
Example:
Gas meter Boiler
≥
425 CFH 195 CFH
* 1 CFH=1,020 Btuh
1
/ " rigid pipe can be used; refer to the sizing tables in the Installation & Operation
2
Manual for limitations. Avoid using
occur.
Heating
Pump
To System
Make-up
Water
1
The end of the / " (NPT) plastic piping should drain into a laundry tub or into a floor
2
drain.
Do not submerge the end of
Note
the pipe in water.
Direct to the external drain
2
Furnace Domestic gas stove
+ +
58.8 CFH 63.7CFH
1
/ " corrugated connectors or tubing as noise may
2
Water Piping Connections
Cold Water
Hot Water
Outlet (DHW) Inlet (DHW)
Auto Feeder Inlet
(Make-up Water)
Space Space Heating
Return
Supply
Gas Connection
Condensate
Outlet
Pressure Relief Valve
Air Separator
Expansion Tank
c
To the
b
Drain via a
a
d
neutralizer
To the laundry tub
External drain
via a condensate pump
>
>
From
System
>
To the laundry tub