A.O. Smith GCV Series Service Handbook page 16

• The connector must be firmly attached and sealed
to prevent it from falling out.
• To aid in removing the connector, a thimble or slip
joint may be used.
• The connector must not extend beyond the inner
edge of the chimney as it may restrict the space
between it and the opposite wall of the chimney
3 FT. MINIMUM
SUPPORT
STRAP
MAINTAIN
CLEARANCE*
SEAL
SLOPE
UP 1/4 IN.
PER FT.
MINIMUM
CHIMNEY TERMINATION VENT SYSTEM
Figure 13
Do not reduce the vent to less than the draft hood
outlet diameter. Do not terminate the vent connector in
a chimney that has not been certified for this purpose.
Some local codes may prohibit the termination of vent
connectors in a masonry chimney.
Vertical Exhaust Gas Vent: Vertical exhaust gas
vents must be installed with U.L. listed type B vent pipe
according to the vent manufacturer's instructions and the
terms of its listing.
It must be connected to the water heater's draft hood by a
listed vent connector or by directly originating at the draft
hood opening.
Vertical gas vents must terminate with a listed cap or
other roof assembly and be installed according to their
manufacturer's instructions.
Gas vents must be supported to prevent damage, joint
separation, and maintain clearances to combustible
materials.
IMPORTANT: This gas vent must be terminated in a
vertical position to facilitate the removal of the burnt
gases.
An unused chimney fl ue or masonry enclosure may be
used as a passageway for the installation of a gas vent.
NOTE: The chimney fl ue or masonry enclosure size may
be too large to allow proper venting.
Common (combined) venting is allowable with vertical
type B vent systems and lined masonry chimneys as long
as proper draft for the water heater is established under
all conditions of operation. CAUTION: DO NOT common
vent this water heater with any power vented appliance.
BASIC INSTALLATION & OPERATION
LISTED LINED
CHIMNEY
2 FT. MINIMUM ABOVE ANY OBJECT
WITHIN 10FT. HORIZONTALLY
DO NOT EXTEND
VENT BEYOND EDGE
OF CHIMNEY
VENT
CONNECTOR
The following fi gures are examples of vent pipe system
installations and may or may not be typical for your
specifi c application. Consult the "National Fuel Gas
Code", NFPA 54, ANSI Z223.1-current edition and the
guidelines set forth by prevailing local codes.
LOWEST DISCHARGE OPENING
LISTED VENT CAP
LISTED GAS VENT
SUPPORT
STRAP
*MAINTAIN
CLEARANCE
VENT
CONNECTOR
SLOPE UP
1/4 IN. PER FT.
MINIMUM
VERTICAL GAS VENT SYSTEM WITH
TYPE B DOUBLE WALL VENT PIPE.
Figure 14
Consult the table found in the "National Fuel Gas
Code", NFPA 54, ANSI Z223.1-current edition to
determine the minimum height from roof to lowest
discharge opening.
MAINTAIN MANUFACTURER'S
SPECIFIED MINIMUM CLEARANCE
SUPPORT
STRAP
*MAINTAIN
CLEARANCE
SEAL
VENT
CONNECTOR
SLOPE UP
1/4 IN. PER FT.
MINIMUM
VENTING THROUGH A CHIMNEY WITH
TYPE B DOUBLE WALL VENT PIPE.
Figure 15
*
Maintain vent pipe clearance requirements to local, state
and/or the "National Fuel Gas Code", ANSI Z223.1(NFPA
54)-current edition.
**
NFPA 211, Standard for Chimneys, Fireplaces, Vents, and
Solid Fuel-Burning Appliances states that these chimneys are
intended to be installed in accordance with the installation
instructions provided with each chimney support assembly.
Minimum air space clearance to combustible materials should be
maintained as marked on the chimney sections.
16
x
12
ROOF PITCH IS x/12
H (MINIMUM) - MINIMUM HEIGHT FROM
ROOF TO LOWEST DISCHARGE OPENING
TYPE B DOUBLE
WALL VENT PIPE
**MAINTAIN
SPECIFIED
CLEARANCE
LISTED VENT CAP
**MAINTAIN
SPECIFIED
CLEARANCE
VENT CONNECTOR
UNUSED CHIMNEY
FLUE OR MASONRY
ENCLOSURE