Advertisement
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 50 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
Adapter
1
Air Vent
2
Bushing
3
PRV-Air Vent
Connection
Clip
Condensate Drain Connection
A condensate drain pipe must be connected to the ¾" condensate outlet fitting at 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.
The Navien NFB boiler comes with an air vent and an
adapter bushing that must be connected to the air vent
connection. The vent efficiently removes the air from
the space heating system.
To secure the adapter to the fitting, install the provided
Pressure
clip after inserting the PRV-air vent adapter into the
Relief Valve
connection on top of the unit.
Air Vent
When installing the air vent, install the air vent bushing
between the air vent and the top connection.
External
LWCO
Before filling the boiler, remove the air vent cap to allow
the system to fill properly. Replace the cap when the
system is full.
Note
Prior to connecting piping to the boiler, flush
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.
Note
Ensure that the vent cap is re-installed and
the vent screws on the system and boiler
pumps are properly tightened before testing
or operating the system.
Condensate trap
Water
Floor drain
Example:
Gas meter
Boiler
≥
425 CFH
195 CFH
* 1 CFH=1,020 Btuh
3
/
" rigid pipe can be used; refer to the sizing tables in the Installation & Operation
4
Manual for limitations. Avoid using
occur.
To System
Make-up Water
Backflow Preventer
Pressure Reducing
The end of the ¾" (NPT) plastic piping should drain into a laundry tub or into a floor
drain.
Note
Do not submerge the end of
the pipe in water.
Direct to the external drain
2
Furnace
Domestic gas stove
+
+
58.8 CFH
63.7CFH
3
/
" corrugated connectors or tubing as noise may
4
Water Piping Connections
Heating
Heating
Supply
Return
Gas
Condensate
Connection
Outlet
Pressure Relief Valve
Air Separator
Pump
Expansion Tank
Valve
c
b
To the drain
a
d
via a
neutralizer
To the laundry tub
External drain
via a condensate pump
>
>
From
System
>
To the laundry tub
Advertisement
