Rheem RTGH-95XLP-2 Use And Care Manual page 35

Venting for Direct-Vent Water Heater
Minimum Vent Length:
Minimum Length
Number of
of 2" or 3" Straight
90° Elbows
Pipe
1 1.0 ft. (0.3 m)
NOTICE:
To use 2" or 4" vent pipe, a reducing adapter or an
increasing adapter will be required.
Warning:
To use Category III Stainless Steel, a proper transition part
will be required to prevent flue gas from leaking.
Depending on the size of pipe that is chosen for venting
the water heater, it might be necessary to use a fitting
for stepping down in pipe size, to connect to the water
heater.
All intake and exhaust venting components must have
the same diameter size. DO NOT use a different size
on the intake and exhaust venting.
The unit may be vented horizontally through a wall
or vertically through the roof. Pipe runs must be
adequately supported along both vertical and horizontal
runs. Maximum unsupported span is recommended
to be no more than 4 feet (1.2 m). It is imperative
that the first hanger be located on the horizontal runs
immediately adjacent to the first 90-degree elbow from
the vertical rise. Only use support isolation hanging
bands. DO NOT use wire to support pipe runs.
Stress levels in the pipe and fittings can be significantly
increased by improper installation. If rigid pipe clamps
are used to hold the pipe in place, or if the pipe cannot
move freely through a wall penetration, the pipe may
be directly stressed, or high thermal stresses may be
formed when the pipe heats up and expands. Install
accordingly to minimize such stresses.
INSTALLATION INSTRUCTIONS
Preexisting Venting Notes:
If the water heater is being installed as a replacement
Minimum Length
for an existing water heater, a thorough inspection of
of 4" Straight
the existing venting and air intake system must be
Pipe
performed prior to any installation work. Verify that the
38.0 ft. (11.6 m)
correct materials, vent lengths, and terminal locations
as described in this 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.
NOTICES:
• It is recommended that the air intake pipe and exhaust
• If the air intake pipe has an upward slope towards the
• Maintain the proper clearance between the vent pipe and
• A clearance of 0 in. (0 cm) is allowed between the vent or
• Use proper support for the vent and air intake pipes.
• It is recommended the support method used isolates the
• DO NOT support, pin, or otherwise secure the venting
See page 36 for additional requirements for the
Commonwealth of Massachusetts.
pipe have a 1/4" per foot upward slope toward the
outdoors.
outdoors, it is required to install a condensate trap as
close as practical to the water heater. See page 43.
A similar condensate trap as described in page 43 is
allowed as long as it prevents rain, condensate or any
other liquid from entering into the water heater. Without a
proper condensate trap, property damage will occur.
combustible or noncombustible materials as described on
pages 28, and 29.
air intake pipe and combustible material.
vent pipe from floor joists or other structural members.
This helps prevent transmission of noise and vibration.
system in a way that restricts the normal thermal
expansion and contraction of the chosen venting material.
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