A.O. Smith RESIDENTIAL GAS WATER HEATERS Instruction Manual page 24

5. Secure assembly to roof structure as shown in Figure E using
field supplied metal strapping or equivalent support material.
note: ensure termination height is above the roof surface or
anticipated snow level (1 ft. in U.S.A. or 1-1/2 ft. in Canada) as
shown in figure c.
6. Install rain cap and small diameter pipe assembly in
roof penetration assembly, Ensure small diameter pipe
i s c e m e n t e d a n d b o t t o m e d i n Y c o n c e n t r i c f i t t i n g .
7. Cement water heater combustion air intake and vent pipes to
concentric vent termination assembly. See Figure E for
proper pipe attachment.
8. Operate heater through 1 heat cycle to ensure combustion air
and vent pipes are properly connected to concentric vent termination
connections.
note: all vent terminations must be the same height when
installing multiple unit venting. If assembly is too short to meet
height requirement, the 2 pipes supplied in the kit may be replaced
by using same diameter, field supplied SDR-26 PVC (D2241) pipe.
Do not extend the 21-1/8" dimension outer pipe to be more than
60 inches, see Figure B.
Do not use field-supplied couplings to extend pipes. Airflow
restriction will occur and the heater pressure switch may cause
intermittent operation.
PROCEDURE 2 SIDE WALL TERMINATION, see Figure F.
1. Determine best location for termination kit.
NOTE: Consideration for the following should be used when
determining an appropriate location for the termination kit:
• Termination kit positioned where the vent vapors will
n o t d a m a g e p l a n t s / s h r u b s o r a i r c o n d i t i o n i n g
equipment.
• Termination kit positioned so it will not be affected by
wind eddy that may allow recirculation of combustion
products, or airborne leaves, or light snow.
• Termination kit positioned where it will not get damaged
or be subjected to foreign objects, such as stones,
balls, etc.
• Termination kit positioned where the vent vapors will
not be objectionable.
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fIGure f.
NOTE: See the venting information (pages 16-20) in this
manual for additional vent location requirements.
2. Cut 1 hole (5 in. diameter)
3. P a r t i a l l y a s s e m b l e c o n c e n t r i c v e n t t e r m i n a t i o n k i t .
a) Cement the Y concentric fitting to larger diameter
kit pipe, see Figure A.
b) Cement the rain cap to the smaller diameter kit
pipe, see Figure A.
note: Instead of cementing the smaller pipe to the rain cap, a
field-supplied stainless steel screw may be used to secure the
2 components together when field disassembly is desired for
cleaning, see figure d.
when using alternate screw assembly method, drill clearance
hole in rain cap and pilot hole in vent pipe for screw being
used. failure to drill adequate holes may cause cracking
of pvc components, allowing combustion products to be
recirculated. failure to follow this warning could result in
personal injury or death.
do not operate the heater with rain cap removed or
recirculation of combustion products may occur. water may
also collect inside larger combustion-air pipe and flow to the
burner enclosure. failure to follow this warning could result
in product damage or improper operation, personal injury
or death.
4. Install Y concentric fitting and pipe assembly through
structure's hole.
note: do not allow insulation or other materials to accumulate
inside pipe assembly when installing through hole.
5. Install rain cap and small diameter pipe assembly in
Y concentric fitting and large pipe assembly. Ensure
small diameter pipe is bottomed and cemented in Y
concentric fitting.
6. Secure assembly to structure as shown in Figure G using field-
supplied metal strapping or equivalent support material.
note: ensure termination location clearance dimensions are as
shown in the diagrams found in Figure 15 A through D. When
extending the length of the 4" pipe, the added length beyond
21-1/8" must be deducted from the maximum equivalent feet of
vent pipe.
note: If assembly needs to be extended to allow side
wall thickness requirement, the 2 pipes supplied in
the kit may be replaced by using same diameter, field-
s u p p l i e d S D R - 2 6 P V C ( D 2 2 4 1 ) p i p e . D o n o t e x t e n d
21 1/8" dimension more than 60 in. (See Figure B.)
Do not use field-supplied couplings to extend pipes. Airflow
restriction will occur and the heater pressure switch may cause
intermittent operation.
7. Cement heater combustion-air and vent pipes to concentric
vent termination assembly. See Figure G for proper pipe
attachment.
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