Rheem AP13945-2 - Manual (Page 9)

Venting
The installation of venting must comply with
national codes, local codes, and the vent
manufacturer’s instructions.
The water heater must be vented to the
outdoors as described in these instructions.
DO NOT connect this water heater to a
Chimney. It must be vented separately from
all other appliances.
All vent components (adapters, pipe, elbows,
terminals, etc.) should be UL1738 Certified
Stainless Steel Venting Material
(e.g. AL29-4C).
Use a vent pipe with an anti-disconnection
joints.
The use of a High Temperature Silicone
(500°F) (260°C) may be required to seal
vent connections. To prevent accidental gas
exhaust leakage, apply a 1/4” (6 mm) wide
bead approximately 1/4” (6 mm) from the
end and another bead against the joint side
of the stop bead.
Follow vent manufacturer’s installation
instructions and their recommended
clearances to combustibles.
The unit can be vented either horizontally or
vertically.
Vent pipe runs must be adequately supported
along both horizontal and vertical runs.
The maximum recommended unsupported
span should be no more than five (5) feet
(1.5 m) Support isolation hanging bands
should be used. DO NOT use wire. (See
Figure below).
Notes on pre-existing vent:
If the water heater is being installed as a
replacement for an existing water heater, a
thorough inspection of the existing venting and
air intake system must be performed prior to
any installation work. Verify that the correct
materials, vent lengths and terminal locations as
detailed in this Use and Care manual have been
met. Carefully inspect the entire venting and air
intake system for any signs of cracks or
fractures, particularly at the joints between
elbows or other fittings and the straight runs of
vent pipe. Check the system for signs of
sagging or other stresses in the joints as a result
of misalignment of any components in the
system. If any of these conditions are found,
they must be corrected in accordance with the
venting instructions in this manual before
completing the installation and putting the
water heater into service.
Additional installation information for The
Commonwealth of Massachusetts is located on
the back page of this manual.
DANGER: Failure to
install the appliance vent
adapter and properly vent
the water heater to the
outdoors as outlined in the
Venting section of this
manual will result in unsafe
operation of the water
heater causing death,
serious injury, explosion, or
fire. To avoid the risk of
fire, explosion, or
asphyxiation from carbon
monoxide, NEVER operate
the water heater unless it is
properly vented and has
adequate air supply for
proper operation as
outlined in the Venting
section of this manual.
Notice: Use a 4” Diameter
UL approved Category III
Stainless Steel vent material
only. No other vent
material is permitted.
WARNING: Refer to
page 7 & 8 for clearances
to combustible material.
!
!
NO! YES!
Venting Lengths
MAXIMUM VENT LENGTH - The
system will not operate if there is excessive
restriction (pressure drop) in the venting
system. A maximum of 47 feet 6 inches
(14.4 m) of vent pipe may be used provided
there is only one 90° elbow in the system. If
additional elbows are required: two elbows
can be used with 42 feet 6 inches (13 m),
and three elbows can be used with 37 feet 6
inches (11.4 m) of vent pipe.
A 90° elbow is equivalent to 5 feet (1.5 m)
of straight pipe. A 45° elbow is equivalent to
2 feet 6 inches (76 cm) of straight pipe
.
The vent should be installed with a slight
downward slope of 1/4” per foot of
horizontal run toward the vent terminal (see
Figure on page 8). This ensures that any
condensate formed during operation of the
unit is evacuated from the appliance.
MINIMUM VENT LENGTH - The vent
length may be as short as one 90° elbow, one
vent adapter, and a Rheem approved vent
termination kit that is installed to the
outdoors through a sidewall.
Number of
90° elbows
(bends)
Maximum
Length of
Straight Pipe
1
2
3
47’ 6”
(14.4 m)
42’ 6”
(13 m)
37’ 6”
(11.4 m)
9