Filling The System - Navien NHB Series Installation & Operation Manual

If option 'b' (p. 28) is selected as the disposal option, the Navien
light commercial condensate neutralizer kit is recommended. The
condensate from the appliance flows through the neutralizing
media and increases the pH of the condensate. An increased pH
prevents corrosion of the installation's drainage system and the
public sewer system.
Installation
The inlet has a center connection port on the side of the unit
and the outlet has a side connection.
Install the neutralizer on the wall or the floor and secure it using
the brackets supplied with the kit.
When mounting on the wall or floor, the neutralizer must be
installed in a horizontal position as shown in Figure 1 below.
Ensure that the condensate runs freely to the drain.
Ensure all connections are made to prevent the backflow of
condensate. Use corrosion resistant piping and secure all piping
to prevent movement.
Do not install condensate piping in areas where the
Note
temperature drops below freezing point. Protect piping
in high pedestrian areas from damage and vibration.
For increased safety when the condensate drain blocks, install
a Y-fitting. Connect the Y-fitting as shown in the installation
diagram and ensure that the condensate runs freely to the drain.
Ensure that the discharge connection is accessible. Access to
the discharge connection is required for maintenance and pH
testing.
If there is insufficient gradient for drainage, install a drainage
pump designed for boiler and water heater condensate removal.
Optional overflow bypass
Figure 1. Horizontal installation
Maintenance
Periodically monitor the level of media in the neutralizer and test
the pH level at the outlet. We recommend an annual pH test using
recognized test strips or an electronic pH meter to obtain precise
measurements. Replace the neutralizing media when the pH drops
below the minimum level required by the local water authority. If
the pH level is not specified, replace the neutralizing media when
the pH is below 6.0. For replacement media, contact your local
Navien distributor.

3.3 Filling the System

Before filling the boiler, completely unscrew and remove the air
vent cap to enable the system to fill properly. Also, loosen the vent
screws on the system and boiler pumps to prevent the air from
being trapped inside the pumps.
Note
Tighten the air vent cap and tighten the vent screws on the pumps
when the system is full.
Relief Valve
Y-Fitting bypass
Note
If the air vent cap is only partially loosened, the air
vent may not allow for the boiler to fully purge. The
cap must be completely unscrewed and removed to
complete the procedure.
Pressure
Air Vent
Air Vent
Bushing
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.
Vent
Screw
Installing the System Piping 29