Navien Backflow Damper (Back-Draft Damper) - Navien NHB-055 Installation & Operation Manual

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.
When using a common vent in a cascade system,
Note
backflow devices are required to prevent exhaust
from entering the building.
Included Items
Backflow Damper
Installation Manual
Ready-Link
communication
cable
Screw (4 ea)
Specifications
Part Name
Part No.
Material
62 Installing a Common Vent System
Cond ensin
g Wate
r Heat er
Co mm
on Ve nt
Ins tal lat Sy ste m
ion Ma
For NPE nu al
Seri es
Wat er
Hea ters
Certified to ANSI
Keep this Z21.10.3 – CSA
required manual for future 4.3. (Only
. referenc for U.S. installat
e whenev er mainten ions)
ance or
WARN ING service is
If the informa
injury, tion in
or death. these instruct
- Do not ions is not followe
store or use gasolin d exactly
- WHAT TO DO e or other , a fire or explosi
Do not ● IF YOU SMELL flamma ble vapors on may result,
try to light GAS and liquids causing propert
Do not ● touch any applian ce. in the damage y , persona
● Immed iately call any electric al switch; vicinity of this l
● If you cannot your gas do not or any other applian
reach your supplie r from use any phone ce.
- Installa tion and gas supplie a neighb in your buildin
service r, call the or's phone. Follow g.
- This entire manua must be perform fire depart the gas
mainte nance l must be left ed by a qualifie ment. supplie r's instruc
- The installa of the commo for the consum d installe tions.
ANSI Z223.1 tion must n vent system er. The r, service agency
/NFPA conform . consum er must or the gas supplie
- When 54. with local codes read and refer to r.
Standa applica ble, the or, in the this manua
rd, Title 24 CFR, installa tion must absenc e of local l for proper
Part 3280, conform codes, the Nationa operati on and
Mobile Homes with the Manufa l Fuel
. ctured Home Gas Code,
Constru ction and
Safety
5.9" (150 mm)
1.1" (28 mm)
Backflow Damper
30014367A
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
Refer to <9.8 Maintenance> for detailed inspection procedures.

Navien Backflow Damper (Back-draft Damper)

When using a common vent in a cascade system,
Note
backflow devices are required to prevent exhaust
from entering the building.
Damper plate
Maintenance port
Gasket
Maintenance port cover
Fix screw