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VENT INSTALLATION CONSIDERATIONS
This water heater can be vented using room air for intake
combustion air, or direct vented so that all intake air for
combustion comes from the outside through a sealed pipe.
The water heater venting may be installed in 4 separate
orientations depending on the requirements of the building and
the water heater. The installer must decide which method is
most appropriate for each installation. These orientations are:
1.
Vertical Termination - vertical vent termination through
unenclosed or enclosed areas with roof penetration, refer
to Vertical Vent Terminal Installation on Page 31.
2.
Through-the-Wall Termination - horizontal vent termination
directly through an outside wall, see Figure 13 on Page 27.
3.
Horizontal Direct Vent - using Through-the-Wall Termination
to exhaust flue products and piping to bring combustion air
to the water heater from the outside. See Figure 15 on
Page 28 and Figure 23 and Figure 24 on page 32.
4.
Vertical Direct Vent - using a vertical vent termination to
exhaust flue products and piping to bring combustion air
to the water heater from outside, see Figure 21 & Figure
22 on Page 32.
In cold climates any water vapor remaining in the flue gases
will condense into a cloud of vapor at the point where the
vent system exits the building. Special consideration is
recommended, before locating the vent termination near
walkways, windows and building entrances.
Direct venting into dead spaces such as alleys, atriums,
and inside corners can cause recirculation of flue gases.
Recirculation of flue gases will cause sooting, and icing of the
combustion air intake during severe cold weather. To prevent
the recirculation of flue gases, maintain as much distance as
possible between the combustion air intake and the exhaust
vent terminal refer to Figure 16 and Figure 17 on Page 29 &
Page 30 respectively.
VENTING INSTALLATION
APPROVED VENT/INTAKE MATERIAL
Approved vent and intake air pipe materials that may be used in
the United States:
PVC pipe materials:
• DWV ASTM-D2665 or CSA B181.2
• Schedule 40, 80, 120 ASTM-D1785 or CSA B137.3
• SDR Series ASTM-2241 or CSA B137.3
CPVC pipe materials:
• CPVC 41 ASTM-D2846 or CSA B137.6
• Schedule 40, 80 ASTM-F441 or CSA B137.6
• SDR Series ASTM-F442
Polypropylene - See page 26
• M & G Duravent PolyPro vent system
• Centrotherm InnoFlue vent system
Approved vent pipe materials that must be used in Canada:
• ULC S636 PVC / CPVC
• ULC S636 Polypropylene - See page 26
Approved intake air pipe materials that must be used in Canada:
PVC pipe materials:
• DWV ASTM-D2665 or CSA B181.2
• Schedule 40, 80, 120 ASTM-D1785 or CSA B137.3
• SDR Series ASTM-D2241 or CSA B137.3
CPVC pipe materials:
• CPVC 41 ASTM-D2846 or CSA B137.6
• Schedule 40, 80 ASTM-F441 or CSA B137.6
• SDR Series ASTM-F442
Polypropylene - See page 26
• M & G Duravent PolyPro vent system
• Centrotherm InnoFlue vent system
NOTE:
The use of cellular core PVC (ASTM F891), cellular core CPVC,
or Radel® (polyphenolsulfone) in non-metallic venting systems is
prohibited. Covering non-metallic vent pipe and fittings with thermal
insulation is prohibited.
If the water heater is being installed as a replacement for an
existing power vented heater in pre-existing venting, a thorough
inspection of existing venting system must be performed prior
to any installation work. Verify that correct material as detailed
above has been used, and that the minimum or maximum vent
lengths and terminal location as detailed in this manual have been
met. Carefully inspect the entire venting system for any signs of
cracks or fractures, particularly at joints between elbows and other
fittings and straight runs of vent pipe. Check system for signs of
sagging or other stresses in 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 installation and putting the water
heater into service.
NOTE: For water heaters in locations with high ambient
temperatures above 100°F (38°C) it is recommended that CPVC or
Polypropylene pipe and fittings be used.
All vent (exhaust) pipes must be pitched a minimum of a 1/4" per
foot back to the water heater to allow drainage of condensation.
Never operate the water heater unless it is vented to the outdoors.
The instructions in this section of the manual must be followed
to avoid choked combustion or recirculation of flue gases. Such
conditions cause sooting of the combustion chamber, burners and
flue tubes and creates a risk of asphyxiation.
For direct vent application where combustion air might be supplied
from cold outdoor ambient temperatures through the fresh air
intake piping system, it is recommended that a backflow preventer
and / or a drain tee be installed in the air intake before proceeding
with installation of the rest of the fresh air intake piping. See the
section on Direct Vent Air Intake Moisture Prevention or call the
technical support phone number listed on the back cover of this
manual for more information.
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