Water Heater Exhaust Terminal Location
The following information should be used for determining the proper location of
the vent terminal for outdoor tankless water heaters.
WARNING
:
Moisture in the flue
gas
will condense as it
leaves the vent t
erminal.
In cold weather this condensate can
fr
eeze
on the exterior wall, under the eaves and on
surr
ounding objects. Some
discoloration to the exterior of
the
building
is to
be
expected. However, i
mpr
oper location
or installation can result in severe
damage
to the structure
or exterior finish of the
building
Additional Considerations
1. Do not install water heater under
any patio or deck.
2. To help prevent moisture from freez-
ing on walls and under eaves, do not
locate the water heater on the side
of a building with prevailing winter
winds.
3. To help prevent water lines from
freezing do not locate water heater
on the side of a building with pre-
vailing winter winds.
4. Do not locate water heater too close
to shrubbery, as flue gases may dam
-
age them.
5. Caulk all cracks, seams and joints
within six (6) feet (1.8 m) of exhaust
vent.
6. Guard exhaust vent against acciden-
tal contact with people and pets.
7. Install the water heater such that the
air inlet and exhaust vent are above
anticipated snow levels
Recess Box Location
- This water heater recess box is intended for an outdoor location only. Follow the
guidelines below or in the Use and Care Manual provided with the water heater for choosing a suitable location.
Figure 1
Figure 2
D
V
V
E
FIXE
D
CLO
SED
OPE
RAB
LE
OPE
RAB
LE
FIXE
D
CLOS
ED
v
v
B
L
F
C
B
v
v
v
X
B
B
B
A
J
C
I
H
X
v
M
K
v
G
A
V VENT TERMINAL
X AIR SUPPLY INLET
AREA WHERE TERMINAL IS NOT PERMITTED
2
(1.8 m)
If soffit vent is too close,
block off and install new
vent at another location
Inside
corner
Caulk
Caulk
Caulk
6' (1.8 m)
caulk zone or to edge of
window etc., starting
within 6' (1.8 m)
Rising moisture will collect under eaves
4'
6' (1.8 m) caulk
zone
6'
(1.2 m)
Canadian Installations
1
Indoor and Outdoor
US Installations
2
Outdoor
A= Clearance above grade, ve-
randa, porch, deck or balcony.
12 inches (30 cm) above antici-
pated snow level.
12 inches (30 cm) above antici-
pated snow level.
B= Clearance to window or door
that may be opened.
6 inches (15 cm) for appliances ≤
10,000 Btuh (3 kW), 12 inches (30
cm) for appliances > 10,000 Btuh
(3kW) and ≤100,000 Btuh (30kW),
36 inches (91 cm) for appliances >
100,000 Btuh (30kW).
6 inches (15 cm) for appliances
≤ 10,000 Btuh (3 kW), 9 inches
(23 cm) for appliances > 10,000
Btuh (3kW) and ≤ 50,000 Btuh
(15kW), 12 inches (30 cm)
for appliances > 50,000 Btuh
(15kW).
C= Clearance to permanently
closed window.
*
*
D= Vertical Clearance to venti-
lated soffit located above the
terminal within a horizontal
distance of 2 feet (61 cm)
from the center line of the
terminal.
*
*
E= Clearance to unventilated
soffit.
*
*
F= Clearance to outside corner.
*
*
G= Clearance to corner.
*
*
H = Clearance to each side of cen-
ter line extended meter/regu-
lator assembly.
3 feet (91 cm) within a height 15
feet (4.57 m) above the meter/regu-
lator assembly.
*
I = Clearance to service regulator
vent outlet.
3 feet (91 cm)
*
J = Clearance to nonmechanical
air supply inlet to building or
the combustion air inlet to any
other appliance.
6 inches (15 cm) for appliances
≤10,000 Btuh (3 kW), 12 inches
(30 cm) for appliances > 10,000
Btuh (3kW) and ≤ 100,000 Btuh
(30kW), 36 inches (91 cm) for ap-
pliances > 100,000 Btuh (30kW).
6 inches (15 cm) for appliances
≤10,000 Btuh (3 kW), 9 inches
(23 cm) for appliances > 10,000
Btuh (3kW) and ≤ 50,000 Btuh
(15kW), 12 inches (30 cm) for
appliances > 50,000 Btuh (15kW)
K = Clearance to mechanical air
supply inlet.
6 feet (1.83 m)
3 feet (91 cm) above if within 10
feet (3 m) horizontally.
L = Clearance above paved
sidewalk or paved driveway
located on public property.
Not Allowed
Not Allowed
M = Clearance under veranda,
porch, deck or balcony.
Not Allowed
Not Allowed
1
In accordance with current CAN/CGA-B149 Installation Code
2
In accordance with current ANSI Z223.1/NFPA National Fuel Gas Code.
* If clearances are not specified, then follow local installation codes and the requirement of the gas supplier.
** For condensing appliances: The vent for this appliance shall not terminate over public walkways, near soffit
vents, crawl space vents, or other areas where condensate or vapor could create a nuisance, hazard or cause
property damage, or where condensate or vapor could cause damage or could be detrimental to the operation
of regulators, relief valves or other equipment.