Navien NFB Series User Manual

71Installing a Common Vent System
9.2 Navien Backflow Damper (Back-draft
Damper)
The Navien backflow damper prevents backflow (back-draft) at the
exhaust vent while the boiler unit operates.
By closing the exhaust vent as soon as the combustion cycle ends,
the Navien backflow damper retains heat in the system for longer
periods. This improves the system’s thermal efficiency.
Note
When using a common vent in a cascade system,
backflow devices are required to prevent exhaust
from entering the building.
Included Items
Backflow Damper
Installation Manual
Condensing Water Heater
Common Vent System
Installation Manual
For NPE Series Water Heaters
Certied to ANSI Z21.10.3 – CSA 4.3. (Only for U.S. installations)
Keep this manual for future reference whenever maintenance or service is
required.
-
Do not store or use gasoline or other ammable vapors and liquids in the vicinity of this or any other appliance.
-
WHAT TO DO IF YOU SMELL GAS
●
Do
not
try to
light any
appliance.
●
Do
not touch any electrical switch;
do
not use any phone
in
your
building.
●
Immediately call your gas supplier from
a
neighbor’s phone. Follow the gas supplier’s
instructions.
●
If
you cannot reach your gas supplier, call the re
department.
-
Installation and service must be performed by a qualied installer, service agency or the gas supplier.
-
This entire manual must be left for the consumer. The consumer must read and refer to this manual for proper operation and
maintenance of the common vent system.
-
The installation must conform with local codes or, in the absence of local codes, the National Fuel Gas Code,
ANSI Z223.1/NFPA 54.
-
When applicable, the installation must conform with the Manufactured Home Construction and Safety
Standard, Title 24 CFR, Part 3280, Mobile Homes.
WARNING
If the information in these instructions is not followed exactly, a re or explosi on may result, causing property damage, personal
injury, or death.
Ready-Link
communication
cable
Screw (4 ea)
Specifications
5.9” (150 mm)
1.1” (28 mm)
Part Name Backflow Damper
Part No. 30014367A
Material PP (Polypropylene)
Maintenance Port
Navien Backflow Damper has a maintenance port to allow you to
easily inspect the operating condition of the damper plate.
Maintenance port
Damper plate
Maintenance port
Gasket
Maintenance port cover
Fix screw
Refer to <9.9 Maintenance> for detailed inspection procedures.
Navien Backflow Damper (Back-draft Damper)
Note
When using a common vent in a cascade system,
backflow devices are required to prevent exhaust
from entering the building.

Navien NFB Series Specifications

General

Brand	Navien
Model	NFB Series
Category	Boiler
Language	English