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28 Installing the System Piping
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
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.
Replace the air vent cap and tighten the vent screws
on the pumps when the system is full.
Vent
Screw
Air Vent Cap
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.
Figure 2. Vertical installation
Y-Fitting
bypass
Optional
overflow bypass
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.
Summary of Contents for NFB-175H
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