20 Installing 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
NHB-055H
NHB-080H
NHB-110H
NHB-150H
Manifold System
GFFM-MSOZUS-001
Pump Specifications
Manufacturer
NHB-055/080/110H
NHB-150H
Grundfos
UPS 15-58
UPS 26-99
Armstrong
Astro 230CI
Astro 280CI
Taco
0015-MSF3-IFC
0013-MSF2-IFC
Wilo
Star S 21F
TOP-S 1.25x25
Bell & Gossett
NRF-25
NRF-36
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 21 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.
