8
Spec
i
f
i
cat
i
ons
Vent
T
ab
l
es
(I
ntake
On
l
y
)
Model Number
Max Intake Vent Length (feet) 3" Max Intake Vent Length (feet) 4"
UCG100H399
2
5
50
W
A
RN
I
NG
!
The
UCG100H399
mode
l
is
not
approved
for
2
inch
diameter
vent
pipe
.
Venting
with
2
inch
pipe
may
resu
l
t
in
damage
to
the
water
heater
or
cause
an
unsafe
condition
.
DO
NO
T
use
2
inch
Vent
Air
I
ntake
Pipe
!
Determ
i
n
i
ng
requ
i
red
i
ntake
vent
l
ength
1
.
Determine
the
tota
l l
ength
of
straight
vent
pipe
(in
feet)
required
for
the
intake
.
2.
Add
5
feet
of
venting
for
every
90°
e
l
bow
.
3
.
Add
2
½
feet
of
venting
for
every
4
5°
e
l
bow
.
4.
T
ota
l
vent
l
ength
cannot
exceed
“
Max
I
ntake
Vent
L
ength
”
on
the
vent
i
ng
tab
l
e
shown
above
.
Examp
l
e
of
T
ota
l I
ntake
Vent
L
ength
for
UCG100
H
3
99 i
nsta
ll
at
i
on
:
A
3”
venting
system
has
a
tota
l
of
two
90
-
degree
e
l
bows
and
a
tota
l
straight
pipe
l
ength
of
10
feet
.
E
quiva
l
ent
vent
l
ength
for
e
l
bows:
2
x
5
feet
=
10
feet
.
T
ota
l
equ
i
va
l
ent
vent
d
i
stance
=
10
feet
+
10
feet
=
20
feet
tota
l
equ
i
va
l
ent
vent
l
ength
. T
h
i
s
i
s
be
l
ow
the
max
i
mum
a
ll
owed
d
i
stance
of
25
feet
for
th
i
s
mode
l
us
i
ng
3
”
vent
.
8
