Navien NFB Series User Manual

21Installing the System Piping
3.1.3 Space Heating System Piping
When connecting the space heating system, follow these guidelines:
●
Carefully tighten all connections to avoid damage to fittings.
●
After installing the boiler, check the space heating system's operation and inspect for leaks.
The optional Navien manifold system enables easy separation of the boiler (primary loop) from the system (secondary loop(s)). Refer to the
illustration below for an example of the piping connections for a Navien manifold system (primary zone).
Space Heating Supply
Space Heating Return
The following tables list the specifications for the available pumps and Navien's manifold system. If you are not using one of the pumps listed
below, you must use a circulator with check valve installed at pump outlet or a pump with an integral check valve.
Model Number
Item NFB-175 NFB-200
NFB-175/200
Manifold System
GXXX001728
Pump Specifications
Model Temp. Rise
Pump Model
Grundfos Taco Bell & Gossett Armstrong
NFB-175
20°F UPS26-99FC
0010-IFC
0013-MSF1-IFC
NRF-36 E7
25°F UPS26-99FC
0010-IFC
0015-MSF1-IFC
NRF-25 E7
35°F UPS15-58FC
005-IFC
0015-MSF1-IFC
NRF-22 Astro 30
NFB-200
20°F UPS26-99FC
0010-IFC
0013-MSF1-IFC
NRF-36 E7
25°F UPS26-99FC
007-IFC
0015-MSF1-IFC
NRF-36 E7
35°F UPS15-58FC
005-IFC
0015-MSF1-IFC
NRF-22 Astro 30
Note
If you are not using one of the pumps listed in the above tables, use a pump with an integral check valve or install a check valve at
the pump outlet. Refer to the performance curve on page 22 to select a pump that suits your application. The boiler can supply
up to a maximum of 2.5 A current at the boiler pump connection terminal.

Navien NFB Series Specifications

General

Type	Condensing Boiler
Fuel Type	Natural Gas or Propane
Heat Exchanger	Stainless Steel
Vent Type	Direct Vent
Vent Diameter	2" or 3"