Navien NHB Series, Installation & Operation Manual

Page: 77 / 135

77 Installing 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
Condens ing Water
Heater
Common Vent System
Installation
Manual
For NPE Se
ries Wa
ter Heat
ers
Certified to ANSI Z21.1
0.3 – CSA 4.
3. (Only for U.S. install
ations)
Keep this ma
nual for fu ture refere
nce when ever main
tenance o
r service is
required.
- Do not stor
e or use gas
oline or oth
er flammab le vapors an
d liquids in
the vicinity of this or a
ny other ap
pliance.
- WHAT TO DO
IF YOU SME LL GAS ● Do not try
to light an y applianc
e.
● Do not to
uch any ele ctrical sw
itch; do not
use any ph one in you
r building
.
● Immediat
ely call yo ur gas sup
plier from
a neighbo r’s phone. F
ollow the g
as supplie r’s instruct
ions.
● If you can
not reach
your gas su pplier, call
the fire de
partment.
- Installation and service
must be pe
rformed by
a qualified installer, se
rvice agency
or the gas s upplier.
- This entire m
anual mus
t be left for the consu
mer. The co
nsumer mu st read and
refer to this ma
nual for pr
oper operat ion and
maintenan
ce of the co mmon vent
system.
- The installa
tion must con
form with lo
cal codes or , in the absen
ce of local
codes, the N
ational Fuel Gas Code,
ANSI Z223.1
/NFPA 54.
- When ap plicable
, the installa
tion must co nform with
the Manufa
ctured Ho me Co
nstruction a nd Safety
Standard, T itle 24 CFR
, Part 3280,
Mobile Ho mes.
WARNI NG
If the info
rmation in these instr
uctions is not followe
d exactly,
a fire or ex plosion ma
y result, c
ausing pro perty damage, pe
rsonal
injury, or d eath.
Condens
ing Water
Heater
Common Ve
nt System Installati
on Manual
For NPE Se
ries Water Heat
ers
Certified t
o ANSI Z21
.10.3 – CSA 4.3. (On
ly for U.S. in stallation
s)
Keep this manual fo
r future ref erence wh
enever ma
intenance or service i
s
required.
- Do not sto
re or use ga
soline or oth er flamm
able vapor
s and liquid s in the vicini
ty of this or
any other ap
pliance.
- WHAT TO D O IF YOU SM
ELL GAS ● Do not try to light an
y applianc
e.
● Do not to uch any ele
ctrical sw
itch; do no t use any p
hone in yo
ur buildin g.
● Immediate
ly call you r gas supp
lier from a
neighbor’ s phone. F
ollow the gas supp
lier’s instru
ctions.
● If you cann
ot reach you
r gas sup plier, call the
fire depa
rtment.
-
Installation and service
must be per
formed by a qualified
installer, se
rvice age ncy or the ga
s supplier.
- This entire m
anual mus t be left for
the consu
mer. The consumer m
ust read and
refer to this m
anual for pro per operat
ion and
maintenan ce of the com
mon vent sys
tem.
- The installa
tion must co
nform with local codes
or, in the ab
sence of loca
l codes, the National Fu
el Gas Cod
e,
ANSI Z223.1/
NFPA 54.
- When applic able, the ins
tallation mu
st conform with the M
anufactured
Home Cons
truction an d Safety
Standard, T
itle 24 CFR
, Part 3280 , Mobile Ho
mes.
WARNING
If the info rmation in
these inst ructions is
not follo
wed exact ly, a fire o
r explosion
may res ult, causin
g propert y damage, pe
rsonal
injury, or d eath.
Ready-Link
communication
cable
Screw (4 ea)
Specifications
8.1” (206 mm)
3” (76 mm)
1.6” (42 mm)
Part Name Backflow Damper
Part No. 30022799A
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.