American Water Heater High Efficiency Commercial Gas HCG Series AHCG3 119T 300 THRU AHCG3 119T 500 Series 200 201 User Manual

							21
• Centrotherm InnoFlue vent system
AL29-4C Stainless Steel - See page 29
•  HeatFab Saf-T Vent
•  Duravent FasNSeal
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.
CATEGORY IV APPLIANCE
Category  IV  appliances  operate  with  a  positive  vent  (exhaust) 
static  pressure  and  with  vent  gas  temperatures  low  enough  to 
produce condensate in the vent piping.
POWER VENT CONFIGURATION
Power  Vent  configurations  derive  all  combustion  air  from  the 
room  where  they  are  installed  and  discharge  all  flue  gases  to 
the  outdoor  atmosphere  through  a  sealed  vent  (exhaust)  pipe. 
Power vent configurations have one vent pipe connected to the 
water  heater  which  can  be  terminated  in  a  vertical  or  horizontal 
arrangement. See Figure 36 and Figure 37 on page 34.
DIRECT VENT CONFIGURATION
Direct  Vent  configurations  derive  all  combustion  air  directly 
from the outdoor atmosphere through a sealed intake air pipe 
and discharge all flue gases to the outdoor atmosphere through 
a  sealed  vent  (exhaust)  pipe.  Direct  Vent  configurations  have 
two pipes connected to the water heater, one vent pipe and one 
intake air pipe. Direct Vent configurations can be terminated in 
one  of  seven  different  arrangements.  See  Figure  38  on  page 
34 through Figure 44 on page 35.
GENERAL VENTING INSTRUCTIONS
These instructions must be followed on all installations.
1.  DO NOT   install  the  water  heater  in  a  Power  Vent 
configuration  unless  there  is  adequate  supply  of  fresh  air, 
see  Air Requirements on page 17. If the installation space 
does not provide an adequate supply of fresh air the water 
heater must be installed in a Direct Vent configuration.
2.  If  the  water  heater  is  to  be  installed  in  a  beauty  shop, 
barber  shop,  cleaning  establishment,  a  laundry  with  dry 
cleaning equipment or any space with contaminated air it is 
imperative that the water heater(s) be installed in a Direct 
Vent configuration so that all air for combustion is derived 
from the outdoor atmosphere.
3.  The vent and intake air piping must terminate outdoors.
4.  The minimum clearance from combustible materials for the 
vent (exhaust) and intake air piping shall be 0 inches. Vent 
piping  passing  through  a  combustible  wall  or  ceiling  must 
be a continuous run (no joints).
5.  The  water  heater  must  be  protected  from  freezing 
downdrafts during shutdown periods.
6.  The vent (exhaust) pipe must not be combined or connected 
to any other appliance’s vent system or chimney.
7.  The intake air pipe must not be combined or connected to 
any other appliance’s intake air piping.
8.  Locate  the  water  heater  where  the  vent  (exhaust)  and 
intake air piping will remain within the maximum equivalent 
lengths allowed. See Venting Requirements on page 22.
9.  Do not install the vent or intake air piping in a manner that 
will allow water to be trapped in the piping.
10.  Vent pipes must be pitched a minimum of a 1/4 inch per foot 
back to the water heater (to allow drainage of condensate).
11.  Do not anchor the vent or intake air pipe directly to framed 
walls, floors or ceilings unless rubber isolation pipe hangers 
are used to prevent vibration noise from being transmitted.
12.  Use only approved vent/intake air pipe sizes and materials. 
See Venting Requirements on page 22.
VENTING INSTALLATION
Breathing carbon monoxide can cause brain damage or death.
Always read and understand the instruction manual .
Install vent system in accordance with codes. 
Do not operate water heater if exposed to flooding or
water damage
Special consideration must be taken with installations
above 10,000 feet (3,048 m) refer to high altitude
section of this manual.
Breathing Hazard - Carbon Monoxide Ga s


Do not operate if soot buildup.Do not obstruct water heater air intake with insulating
jacket or blanket.
Do not place chemical vapor emitting products near
water heater.
Gas and carbon monoxide detectors are available.Never operate the heater unless it is vented to th e
outdoors and has adequate air supply to avoid risks
of improper operation, fire, explosion or asphyxiation .
Analyze the entire vent system to make sure that
condensate will not become trapped in a section of
vent pipe and therefore reduce the open cross
sectional area of the vent. 
Never  operate  water  heater  unless  it  is  vented  to  the  outdoors. 
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.
GENERAL VENTING INFORMATION
The  water  heaters  covered  in  this  manual  are  operationally 
equivalent  to  Category  IV  appliances  and  may  be  installed  in 
either a Power Vent or Direct Vent configuration.
APPROVED MATERIALS
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-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 28
•  M & G Duravent Polypro vent system
•  Centrotherm InnoFlue vent system
AL29-4C Stainless Steel - See page 29
•  HeatFab Saf-T Vent
•  Duravent FasNSeal
Approved vent pipe materials that must be used in Canada:
•  ULC S636 PVC / CPVC
•  ULC S636 Polypropylene - See Page 27.
•  AL29-4C Stainless Steel - See Page 28.
Intake air pipe materials that may 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 28
•  M & G Duravent Polypro vent system  
						

							22
Six Inch Pipe
The  water  heaters  covered  in  this  manual  are  certified  to 
a  maximum  length  of  6  inch  pipe  for  the  exhaust  venting 
arrangement  of  120  equivalent  feet  (36.5  m).  The  certified 
maximum  length  of  6  inch  pipe  for  intake  air  piping  is  also  120 
equivalent  feet  (36.5  m).  IE:  On  Direct  Vent  installations  both 
pipes can be up to 120 equivalent feet (36.5 m).
INTAKE AIR AND VENT PIPE CLEARANCES
The minimum clearance from combustible materials for the vent 
(exhaust) and intake air piping shall be 0 inches. Vent or intake 
air piping passing through a combustible wall or ceiling must be 
a continuous run (no joints).
MINIMUM EQUIVALENT LENGTHS
Four Inch Pipe
The  water  heaters  covered  in  this  manual  are  certified  to 
a  minimum  length  of  4  inch  pipe  for  the  vent  (exhaust)  of  15 
equivalent  feet  (4.6  m).  There  is  no  minimum  equivalent  feet 
requirement for the intake air pipe.
Six Inch Pipe
The  water  heaters  covered  in  this  manual  are  certified  to 
a  minimum  length  of  6  inch  pipe  for  the  vent  (exhaust)  of  70 
equivalent  feet  (21.3  m).  There  is  no  minimum  equivalent  feet 
requirement for the intake air pipe.
MAXIMUM NUMBER OF ELBOWS
The vent pipe may have a maximum of six 90° elbows installed. 
The  intake  air  pipe  may  have  a  maximum  of  six  90°  elbows 
installed. IE: in a Direct Vent configuration each pipe can have up 
to six (6) 90° elbows installed. Two (2) 45° elbows equal one (1) 
90° elbow. Each 90° elbow is equivalent to 5 feet (1.5 m) of linear 
pipe, 45° elbows are equivalent to 2.5 feet (0.75 m) of linear pipe.
Note:  Refer  to Table  10  and Table  11  for  equivalent  linear  pipe 
length of AL29-4C
® 45° and 90° elbows.
FACTORY SUPPLIED FITTINGS
The  water  heater  ships  with  two  (2)  factory  supplied  4  inch 
terminations  (PVC  45°  elbows  with  debris  screen).  Factory 
supplied  vent  and  intake  air  terminations  or  concentric  and  low 
profile terminations must be used. Factory supplied terminations 
and  installed  fittings  (exhaust  elbow  and  intake  air  connection) 
add zero equivalent feet to the vent and intake air piping.
NOTE:  3  inch  vent  and/or  intake  pipe  as  well  as  3  inch 
terminations  previously  used  on  older  (A)HCG3  119T  300/400 
models must be replaced with 4 inch or 6 inch pipe and 4 inch or 
6 inch terminations depending on installed length.
TABLE 7-PVC/CPVC and Polypropylene
Number of 
90° Elbows  Installed 4 Inch Pipe
6 Inch Pipe
Maximum Feet (Meters) Maximum Feet (Meters)
One (1) 65 feet (19.8 meters) 115 feet (35.0 meters)
Two (2) 60 feet (18.2 meters) 110 feet (33.5 meters)
Three (3) 55 feet (16.8 meters) 105 feet (32.0 meters)
Four (4) 50 feet (15.2 meters) 100 feet (30.5 meters)
Five (5) 45 feet (13.7 meters) 95 feet (29.0 meters)
Six (6) 40 feet (12.2 meters) 90 feet (27.4 meters)
6 INCH EXTENDED VENT TERMINATIONS
When 6 inch intake air or vent pipe is installed using standard 
terminations,  factory  supplied  6  inch  terminations  must  be 
used. Contact your local distributor or call the parts department 
(phone number listed on the back cover of this manual) to order 
6  inch  termination(s).  See  Optional  Direct  Vent  Terminations 
on page 12.
13. Use only factory supplied vent and intake air, concentric or low 
profile terminations. See Venting Requirements on page 22.
14.  Do not locate the vent (exhaust) or intake air terminations 
where  they  would  be  objectionable  due  to  noise  at  the 
termination(s).  This  includes  locations  close  to  or  across 
from windows and doors.
15.  Direct venting into dead air spaces such as alleys, atriums, 
and  inside  corners  can  cause  recirculation  of  flue  gases. 
Recirculation  of  flue  gases  will  cause  sooting,  premature 
failure  of  the  heat  exchanger  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 intake air and vent terminations.
16.  Do not locate the vent termination over a public area where 
condensate or vapor can cause a nuisance or ice hazard.
17.  Ensure the screens in the factory supplied terminations are 
securely installed to prevent blockage in the vent system.
18.  Stress  levels  in  pipe/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 stressed, or high 
thermal  stresses  may  be  formed  when  the  pipe  heats  up 
and expands. Install accordingly to minimize such stresses.
19.  Carefully  read  Venting  Requirements  on  page  22  and  then 
proceed to the Venting Installation Sequence on page 23.
VENTING REQUIREMENTS
FIELD SUPPLIED FITTINGS
Field supplied fittings should be equivalent to the piping material 
being installed. Field installed/supplied fittings will add equivalent 
feet  to  the  vent  or  intake  air  piping  as  indicated  below. All  field 
supplied/installed  fittings  and  piping  must  be  factored  into  the 
equivalent feet calculations. 
•  90° elbows (short or long radius) are equivalent to 5 linear 
feet (152 cm) of pipe. 
•  45° elbows (short or long radius) are equivalent to 2.5 linear 
feet (76 cm) of pipe.
Note:  Refer  to Table  10  and Table  11  for  equivalent  linear  pipe 
length of AL29-4C
® 45° and 90° elbows.
PRIMER AND CEMENT
Tetrahydrofuran  (THF)  primer  should  be  used  to  prepare  the 
surfaces of pipe and fittings for solvent welding. If CPVC pipe and 
fittings are used, then the proper cement must be used for all joints, 
including joining the pipe to the factory provided terminations (PVC 
material). PVC Materials should use ASTM D-2564 Grade Cement; 
CPVC Materials should use ASTM F-493 Grade Cement.
PIPE SIZE REQUIREMENTS
The water heaters covered in this manual are certified for the use 
of 4 and 6 inch pipe for the vent (exhaust) and intake air piping. 
If  the  installed  equivalent  length  for  the  intake  air  or  vent  piping 
will be 70 feet (21.3 m) or less, 4 inch pipe must be used. If the 
installed equivalent length will be more than 70 feet (21.3 m), 6 
inch pipe must be used.
NOTE:  Install  the  pipe  size  required  for  the  installed  equivalent 
length of each pipe independently. IE: If the intake air pipe will be 
70 equivalent feet or less and the vent pipe will be more than 70 
equivalent feet; the intake air pipe must be installed using 4 inch 
pipe and the vent must be installed using 6 inch pipe.
MAXIMUM EQUIVALENT LENGTHS
Four Inch Pipe
The  water  heaters  covered  in  this  manual  are  certified  to  a 
maximum length of 4 inch pipe for the exhaust venting arrangement 
of  70  equivalent  feet  (21.3  m).  The  certified  maximum  length  of 
4  inch  pipe  for  intake  air  piping  is  also  70  equivalent  feet  (21.3 
m).  IE:  On  Direct  Vent  installations  both  pipes  can  be  up  to  70 
equivalent feet (21.3 m).   
						

							23
9. All vent (exhaust) pipes must be pitched a minimum of a 1/4 
inch  per  foot  back  to  the  water  heater  (to  allow  drainage  of 
condensate).
10.  If  installing  4  inch  vent  pipe  connect  the  vent  pipe  to  the 
exhaust elbow on the water heater.
11.  If  installing  6  inch  pipe  transition  to  4  inch  pipe  as  shown  in 
Figure  15.  The  field  installed  4”  pipe  between  the  exhaust 
elbow and the 6” x 4” reducer coupling should be 18 inches 
(45 cm) or less in length.
DIRECT VENT INSTALLATION
1. Read the General Venting Instructions on page 21 and Venting 
Requirements on page 22 before proceeding. These instructions 
and requirements must be followed in addition to the instructions 
below that are specific for Direct Vent configurations.
2.  Determine  which  Direct  Vent  arrangement  will  be  used  for 
the installation. There are seven (7) Direct Vent arrangement 
options, see pages 34 and 35.
3.  Determine  vent  and  intake  air  pipe  size  to  be  used  for  the 
installation; see Venting Requirements on page 22.
4.  Plan  the  layout  of  the  vent  and  intake  air  piping  backwards 
from  the  termination  point  outdoors  to  the  water  heater. 
Layout  the  vent  and  intake  air  piping  to  use  a  minimum  of 
pipe and elbows.
5.  Install the terminations first. 
If  standard  terminations  are  being  used  and  the  intake  air 
or  vent  piping  will  terminate  vertically,  through  a  roof,  see 
Vertical Termination Installation on page 24. 
If standard terminations are being used and the intake air or 
vent piping will terminate horizontally, through a sidewall, see 
Sidewall Termination Installation on page 26. 
If  a  concentric  termination(s)  will  be  used  see  Concentric 
Termination Installation on page 29. If a low-profile termination 
will be used see Low Profile Termination Table 12 on page 33.
6.  When  installation  of  the  termination(s)  is  complete  Install 
necessary piping and fittings to route the intake air and vent 
piping back to the water heater.
7.  The  intake  air  and  vent  piping  must  be  supported  properly 
to  avoid  bending  or  failure.  The  water  heater  manufacturer 
recommends that the vent and intake air piping be supported 
every 5 feet (152 cm) of vertical run and every 3 feet (91 cm) 
of horizontal run.
8.  Do not install the vent or intake air piping in a manner that will 
allow water to be trapped in the piping.
9.  A  field  supplied  condensate  Tee  fitting  and  drain  hose  must 
be  installed  in  the  intake  air  piping  near  the  water  heater  in 
colder climates with heavy snow accumulations and in areas 
that regularly experience high humidity. The drain hose must 
be routed to an adequate floor drain separate from any other 
condensate drains. See Figure 16 on page 24.
NOTE: Snow being pulled into the intake air piping and then 
melting can lead to excessive amounts of water accumulation 
and damage water heater components. Warm, humid outdoor 
air  can  lead  to  excessive  condensation  inside  the  intake  air 
piping and may also damage water heater components.
10.  All vent (exhaust) pipes must be pitched a minimum of a 1/4 
inch  per  foot  back  to  the  water  heater  (to  allow  drainage  of 
condensate).
11.  If  installing  4  inch  vent  pipe  connect  the  vent  pipe  to  the 
exhaust elbow on the water heater.
12.  If  installing  6  inch  vent  pipe  transition  to  4  inch  pipe  at  the 
exhaust  elbow  on  the  water  heater  as  shown  in  Figure  15. 
The  field  installed  4”  pipe  between  the  exhaust  elbow  and 
the 6” x 4” reducer coupling should be 18 inches (45 cm) or 
less in length.
The  water  heaters  covered  by  this  manual  may  be  installed  in  a 
Direct  Vent  configuration  using  a  6  inch  concentric  or  6  inch  low 
profile termination.
Contact your local distributor or call the parts department phone 
number listed on the back cover of this manual to order.
•  6” Concentric Termination Part # 9008841005
•  6" Low Profile Termination Part # 9008935005
VENTING INSTALLATION SEQUENCE
1.  Read the General Venting Instructions on page 21 and Venting 
Requirements on page 22 before proceeding. These instructions 
and requirements must be followed on all installations.
2.  Determine  whether  the  water  heater  will  be  installed  in  a 
Power Vent or Direct Vent configuration and which vent system 
arrangement  will  be  used  for  the  installation.  See  the  various 
venting arrangements on pages 34 and 35.
3.  Proceed  to  the  applicable  installation  instructions  that  follow;  
Power Vent Installation or Direct Vent Installation.
POWER VENT INSTALLATION
1. Read  the  General  Venting  Instructions  on  page  21  and 
Venting Requirements on page 22 before proceeding. These 
instructions  and  requirements  must  be  followed  in  addition 
to  the  instructions  below  that  are  specific  for  Power  Vent 
configurations.
2.  Determine  which  Power  Vent  arrangement  will  be  used  for 
the installation; vertical or horizontal termination. See Figure 
36 and Figure 37 on page 34.
3.  Determine the vent pipe size for the installation, see Venting 
Requirements on page 22.
4.  Plan  the  layout  of  the  vent  piping  backwards  from  the 
termination  point  outdoors  to  the  water  heater.  Layout  the 
vent piping to use a minimum of pipe and elbows.
5.  Install the termination first.
If the vent piping will terminate vertically, through a roof, see 
Vertical Termination Installation on page 24. 
If  the  vent  piping  will  terminate  horizontally,  through  a 
sidewall, see Sidewall Termination Installation on page 26.
4” PIPE FIELD SUPPLIED
ALUMINUMEXHAUST/
CONDENSA TE
ELBOW VENT
CONNECTION
FA CT OR Y
INST ALLED 6” PIPE FIELD
SUPPLIED
6” x 4” REDUCER
FIELD SUPPLIED
VENT (EXHAUST) CONNECTION
Figure 15
6.  When  installation  of  the  termination  is  complete  install 
necessary piping and fittings to route the vent piping back to 
the water heater.
7.  The  vent  pipe  must  be  supported  properly  to  avoid  bending 
or  failure.  The  water  heater  manufacturer  recommends  that 
the vent pipe be supported every 5 feet (152 cm) of vertical 
run and every 3 feet (91 cm) of horizontal run.
8.  Do not install the vent piping in a manner that will allow water 
to be trapped in the piping.  
						

							24
14. If installing 4 inch intake air pipe connect the intake air pipe to 
the intake air connection on the water heater.
15.  If installing 6” intake air pipe transition to 4” pipe at the intake 
air  connection  on  the  water  heater  as  shown  in  Figure  18. 
The field installed 4” pipe between the intake air connection 
and the 6” x 4” reducer coupling should be 18 inches (45 cm) 
or less in length.
3” PIPE F ACTORY
INST ALLED
6” PIPE FIELD
SUPPLIED 4” PIPE FIELD
SUPPLIED
6” x 4” REDUCER
FIELD SUPPLIED 4” x 3” REDUCER
FA
CT OR Y INST ALLED
INT AKE  AIR CONNECTION
INT AKE  AIR CONNECTION
INT
AKE  AIR
COMBUSTION
BLOWER
Figure 18
VERTICAL TERMINATION INSTALLATION
1.  Determine the location for the termination(s).
2.  If  installing  only  the  vent  (exhaust)  piping  in  a  Power  Vent 
configuration  vertically  through  the  roof;  ensure  that  all 
exterior  vertical  clearance  requirements  shown  in  Figure 
19  and  Figure  20  on  page  25  are  being  maintained.  These 
clearances and those cited by local and national codes must 
be maintained.
NOTE: On flat roof installations the vent termination must be 
a minimum of 24 inches (60 cm) above any parapet, vertical 
wall or structure within 10 feet (3 m) horizontally. See Figure 
20 on page 25.
3.  If  installing  both  intake  air  and  vent  piping  in  a  Direct  Vent 
configuration  vertically  through  the  roof;  ensure  that  all 
exterior  vertical  clearance  requirements  shown  in  Figure 
20  and  Figure  21  on  page  25  are  being  maintained.  These 
clearances and those cited by local and national codes must 
be maintained.
NOTE:  On  flat  roof  installations  the  intake  air  and  the  vent 
terminations must be a minimum of 24 inches (60 cm) above 
any  parapet,  vertical  wall  or  structure  within  10  feet  (3  m) 
horizontally. See Figure 20 on page 25.
4.  If  installing  only  vent  piping  in  a  Power  Vent  configuration 
vertically  through  the  roof  the  following  instructions  must  be 
followed:
The  vent  termination  must  be  oriented  facing  downward  as 
shown in Figure 19 and Figure 20 on page 25.
The bottom edge of the vent termination must be a minimum 
of  12  inches  (30  cm),  18  inches  (45  cm)  in  Canada,  above 
the  average  or  expected  snow  level  as  shown  in  Figure  19 
on page 25. 
5.  If  installing  both  intake  air  and  vent  piping  in  a  Direct  Vent 
configuration  vertically  through  the  roof  the  following 
instructions must be followed:
The intake air and vent pipes must penetrate the same side 
of the roof as shown in Figure 21 on page 25.
The intake air and vent terminations must be oriented facing 
downward  and  in  the  same  direction  as  shown  in  Figure  21 
on page 25.
The  intake  air  and  vent  terminations  must  have  a  minimum 
INT AKE  AIR CONDENSA TE TEE INST ALLATION
INSTALL TEE FITTING  AS CLOSE
TO  WA TER HEAT ER INTAKE AIR
CONNECTION  AS POSSIBLE
FIELD SUPPLIED
4” x 4 ” x 1/2”  TEE
WITH HOSE BARB
FITTING INST ALLEDFA
CT OR Y
INST ALLED
INT AKE  AIR
CONNECTION
(4” x 3” REDUCER)
INT AKE  AIR
CONNECT  FIELD
SUPPLIED FLEXIBLE
DRAIN HOSE  TO BARB
FITTING  AND FORM  A
LOOP  WATER  TRAP  IN
DRAIN HOSE
RUN DRAIN HOSE
TO  SUIT ABLE FLOOR
DRAIN SEP ARATELY
FROM OTHER
CONDENSA TE DRAINS
Figure 16
13.  Ensure the Intake Air Screen on the Intake Air Connection is 
removed  before  connecting  the  intake  air  pipe  to  the  water 
heater, see Figure 17. 
Do not obstruct water heater air intake.
Gas and carbon monoxide detectors
are available.
Install water heater in accordance with
the instruction manual.
Breathing carbon monoxide can cause brain damage or
death.  Always read and understand instruction manual.
Breathing Hazard - Carbon Monoxide Ga s
NOTE:  Do  not  leave  the  screen  inside  the  Intake  Air 
connection  in  Direct  Vent  installations.  Once  the  intake  air 
pipe  is  installed  the  screen  will  be  hidden  from  view  and 
may  become  clogged  with  debris  over  time.  This  will  cause 
improper combustion.
INTAKE  AIR CONNECTION DET AIL
4” x 3” REDUCER
COUPLING - F ACTORY INST ALLED
INTAKE  AIR SCREEN(remove for Direct V ent)
Figure 17  
						

							25
INTAKE  AIR AND/OR VENT
TERMINA TION(S) MUST  BE A 
MINIMUM OF 24 INCES (60 cm) 
ABOVE  ANY PARAPET, VERTICAL
WA LL OR STRUCTURE WITHIN
10 FEET  (3 m) HORIZONT ALLY.
VERTICAL  TERMINATION(S) FLA T ROOF CLEARANCEINTAKE  AIR AND/OR VENT  (EXHAUST)
24 INCHES (60 cm)
MINIMUM HEIGHT  ABOVE
IF LESS 
THAN
10 FEET  (3 m)
Figure 20
11.  Return to Power Vent Installation on page 23 or Direct Vent 
Installation  on  page  23  to  complete  the  installation  of  the 
intake air and/or vent piping between the termination(s) and 
the water heater.
VERTICAL  TERMINATION - DIRECT VEN TSTANDARD  TERMINATIONS
24 INCHES (61 cm) MINIMUM
48 INCHES (122 cm) IN COLDER CLIMA TES
FA CT OR Y SUPPLIED
ST ANDARD  TERMINATIONS
POINTED DOWNW ARD
FIELD
SUPPLIED
90° ELBOW
VENT  (EXHAUST)
TERMINA TION INT
AKE  AIR
TERMINA TION
FIELD SUPPLIED
PLUMBING
ROOF BOOTS
OR FLASHINGS
MAINTA IN 12” (30 cm)
18” (45 cm) FOR CANADA
MINIMUM CLEARANCE
ABOVE HIGHEST  
ANTICIPA TED SNOW LEVEL.
Figure 21
separation of 24” (61 cm) measured on center line as shown 
in  Figure  21  on  page  25.  In  colder  climates  this  separation 
should be increased to at least 48 inches (122 cm).
The  bottom  edge  of  the  intake  air  and  vent  terminations 
must be a minimum of 12 inches (30 cm), 18 inches (45 cm) 
in  Canada,  above  the  average  or  expected  snow  level  as 
shown in Figure 19 and Figure 21 on page 25.
6.  When  the  intake  air  and/or  vent  piping  from  multiple 
water  heaters  will  terminate  in  the  same  location  the  vent 
terminations  can  be  grouped  together  in  close  proximity  0 
inches/touching. Intake air terminations can also be grouped 
together in close proximity 0 inches/touching. 
The  distance  between  the  closest  vent  and  intake  air 
terminations  must  be  a  minimum  of  24  inches  (61  cm)  as 
shown in Figure 21. In colder climates this separation should 
be increased to at least 48 inches (122 cm).
7.  Cut a 5 inch (13 cm) diameter hole for 4 inch pipe or 7 inch 
(18  cm)  diameter  hole  for  6  inch  pipe  where  the  pipe(s)  will 
pass through the roof.
NOTE: Beware of concealed wiring and piping when cutting 
through the roof.
8.  Suspend  the  pipe(s)  through  center  of  hole  using  field 
supplied  metal  strapping  or  equivalent  support  materials  as 
shown in Figure 19.
9.  Slide  a  roof  boot  or  equivalent  flashing  over  the  pipe  and 
secure roof boot or equivalent flashing to roof (see Figure 19) 
and seal around the flashing.
10.  Install the factory supplied intake air and/or vent termination(s) 
using field supplied pipe and one field supplied 90° elbow as 
shown  in  Figure  19. The  short  section  of  pipe  that  connects 
between the field supplied 90° elbow and the factory supplied 
termination  must  not  be  excessive  in  length.  The  exposed 
portion  of  this  pipe  shall  be  no  more  than  2  inches  (5  cm), 
see Figure 19.
2” (5 cm)
MAXIMUM FACT OR Y SUPPLIED
ST ANDARD  TERMINATION
POINTED DOWN  TOWA RDS
THE GROUND
VERTICAL  TERMINATION(S) INST ALLATIONINTAKE  AIR AND/OR VENT  (EXHAUST)
FIELD
SUPPLIED
90° ELBOW
FIELD
SUPPLIED
STRAP/SUPPOR T
FIELD SUPPLIED
PLUMBING
ROOF BOOT
OR FLASHING
MAINTAIN 12” (30 cm)
18” (45 cm) FOR CANADA
MINIMUM CLEARANCE
ABOVE HIGHEST  ANTICIPAT ED
SNOW LEVEL.
Figure 19  
						

							26
SIDEWALL TERMINATION INSTALLATION
1. Determine the location for the termination(s).
2.  If  installing  only  vent  (exhaust)  piping  in  a  Power  Vent 
configuration  through  a  sidewall;  ensure  that  all  exterior 
sidewall  clearance  requirements  for  the  termination,  shown 
in  Figure  45a  on  page  36,  are  being  maintained.  These 
clearances and those cited by local and national codes must 
be maintained.
3.  If  installing  both  intake  air  and  vent  piping  in  a  Direct  Vent 
configuration  through  a  sidewall;  ensure  that  all  exterior 
sidewall  clearance  requirements  for  the  terminations, 
shown in Figure 45b on page 37, for the vent and intake air 
termination  are  being  maintained.  These  clearances  and 
those cited by local and national codes must be maintained. 
4.  If installing both an intake air and vent termination in a Direct 
Vent configuration through a sidewall there must be a minimum 
of 24 inches (61 cm) separation, measured on vertical center 
line, between the intake air and vent terminations, see Figure 
22.
NOTE:  In  colder  climates  this  separation  should  be 
increased  to  at  least  48  inches  (122  cm)  between  the 
intake air and vent termination or any other appliance vent 
that discharges moisture-laden air such as clothes dryers. 
This  will  reduce  possibility  of  frost  over  from  side  winds 
blowing exhaust vapors to the intake air termination and is 
recommended for Canadian installations.
5.  If  installing  both  intake  air  and  vent  terminations  in  a  Direct 
Vent  configuration  through  a  sidewall  the  intake  air  and 
vent  terminations  must  be  installed  at  the  same  elevation 
measured on horizontal center line - see Figure 22.
VENT (EXHAUST)
TERMINA TION INT
AKE  AIR
TERMINA TION
INST ALL ON
ELEVATION
CENTERLINE
24 INCHES (61 cm) MINIMUM
48 INCHES (122 cm) IN COLDER CLIMA TES
KEEP INTAKE AND VENT
TERMINAT ION SCREENS
CLEAR OF DEBRIS
SIDEWA LL TERMINA TION - DIRECT  VENT
STANDARD  TERMINATIONS
Figure 22
6.  When  the  intake  air  and/or  vent  piping  from  multiple  water 
heaters will terminate at the same location through a sidewall, 
the  vent  terminations  can  be  grouped  together  in  close 
proximity  -  0  inches/touching.  The  intake  air  terminations 
can  also  be  grouped  together  in  close  proximity  -  0  inches/
touching. 
However,  the  distance  between  the  closest  vent  and  intake 
air  terminations  must  be  a  minimum  of  24  inches  (61  cm). 
In  colder  climates  this  separation  should  be  increased  to  at 
least 48 inches (122 cm). See Figure 22. 7. 
Cut a 5 inch (13 cm) diameter hole for 4 inch pipe or 7 inch 
(18  cm)  diameter  hole  for  6  inch  pipe  where  the  pipe(s)  will 
pass through the wall.
NOTE: Beware of concealed wiring and piping when cutting 
through the wall.
8.  Cut  a  length(s)  of  pipe  being  installed  3.5  inches  (8.9  cm) 
to 9.5 inches (24.1 cm) longer than the wall thickness at the 
opening. See Figure 23.
NOTE:  Vent  Termination  –  exhaust  gases  of  this  water 
heater  are  less  than  140°F.  In  cold  climates  water  vapor  in 
the exhaust gases will condense into a cloud of vapor where 
the vent exits the building. This vapor can gradually discolor 
exterior  building  surfaces.  The  vent  termination  should  be 
located  where  this  vapor  cloud  and  potential  discoloration 
are not a  concern. Extending the exposed vent piping up to 
a maximum of  6 inches (15.2 cm)  from the wall helps vapor 
from  being  trapped  along  a  building’s  face.  To  avoid  this 
problem,  the  vent  can  also  be  terminated  vertically  through 
the roof, see Vertical Termination Installation on page 24.
9.  Cement the intake air and/or vent termination to the section(s) 
of pipe cut to length in the above Step.
10.  Slide the included metal wall plate(s) over the pipe(s) to stop 
against  the  intake  air  and/or  vent  termination.  Place  some 
silicone  caulking  (field  supplied)  on  the  back  of  the  wall 
plate(s) to secure it to the wall.
11.  Working  from  outside,  slide  the  pipe  and  termination(s) 
assembled  in  the  above  steps  through  the  wall.  Ensure  the 
termination(s)  is  pointed  down  towards  the  ground.  See 
Figure 23.
INTERIOR WA LL EXTERIOR WALL
FROM
WA
TER
HEAT ER
COUPLING
SIDEWA LL TERMINA TION INST ALLATION
 INTAKE  AIR AND/OR VENT (EXHAUST)
MET AL PLAT ES
INST ALL INSIDE
AND/OR OUTSIDE
FACT OR Y SUPPLIED
ST ANDARD  TERMINATION
POINTED DOWN 
TO WA RDS  THE GROUND
INCREASE EXPOSED VENT
PIPING UP
 TO A MAXIMUM
OF 6 INCHES (15.2 cm) FROM  
WA LL TO  HELP  PREVENT V APOR
FROM DISCOLORING  THE WALL
SURF ACE IN COLDER CLIMA TES
Figure 23
12.  Place a bead of silicone caulking (field supplied) around the 
gap between the installed pipe(s) and the wall. Apply enough 
to fill the gap between the pipe(s) and wall.
13.  Press the wall plate flush against the outside wall.
14.  Working  from  the  inside  apply  enough  silicone  caulking  on 
the  back  of  the  interior  wall  plate(s)  to  hold  it  in  place  and 
slide the wall plate over the installed pipe(s).
15.  Install a coupling to the end of the pipe(s) inside the building. 
Before  the  silicone  caulking  has  time  to  completely  set  go 
outside  the  building  and  ensure  the  termination(s)  is  still 
pointing down towards the ground. See Figure 23.
16.  Return to Power Vent Installation on page 23 or Direct Vent 
Installation  on  page  23  to  complete  the  installation  of  the 
intake air and/or vent piping between the termination(s) and 
the water heater.  
						

							27
Installations  must  comply  with  applicable  national,  state,  and 
local codes. For Canadian installation, Polypropylene vent must 
be listed as a ULC-S636 approved system. If Polypropylene vent 
is  not  required  by  your  local  code,  you  may  use  either  PVC  or 
CPVC pipes for your water heater that allows non-metallic venting 
material installations.
Polypropylene vent systems do not use cement to connect the pipe 
and elbow sections but use a push together gasket seal method. 
Do not attempt to connect Polypropylene with sealant cement. All 
vent  connections  MUST  be  secured  by  the  vent  manufacturer’s 
joint  connector.  The  installer  must  use  a  specific  vent  starter 
adapter  at  the  flue  connection.  The  adapter  is  supplied  by  the 
vent manufacturer to adapt to its vent system.
In order to be in full compliance with UL 1738 or ULC-S636 and 
to meet the requirements of the water heater manufacturer, you 
must  use  the  metal  joint  connector  rings,  available  from  the 
Polypropylene  vent  manufacturer,  to  stiffen  the  joints  of  4”  and 
6” diameter pipes.POLYPROPYLENE INSTALLATIONS
The  water  heaters  covered  by  this  manual  have  been 
approved  to  be  installed  with  Polypropylene  vent  material 
as shown in Table 8 and Table 9. The approved application 
of  single  wall,  non-flexible,  non-concentric  Polypropylene 
vent  material  is  offered  by  two  specific  manufacturers 
(Centrotherm ECO Systems and DuraVent Polypropylene). 
These listed products must be installed by following the vent 
manufacturer’s instructions. Refer to Table 7-PVC/CPVC and 
Polypropylene on Page 22 to determine the maximum pipe 
length and number of elbows that can be used.
Insulation should not be used on Polypropylene venting materials. 
The use of insulation will cause increased vent wall temperatures, 
which could result in vent pipe failure.
Use  only  the  adapters  and  vent  system  listed  in  Tables  below. 
DO  NOT  mix  vent  systems  of  different  types  or  manufacturers. 
Failure to comply could result in severe personal injury, death, or 
substantial property damage.
TABLE 8
M & G Duravent PolyPro Vent system part numbers
Nominal Pipe  Diameter Flue Outlet 
Adapter Adapter 
Connector Ring 
Connector 90 Degree Elbow
Vent Material Vent Terminal(s)
4” 4PPS-AD PPS-PAC4PPS-LB4PPS-E90B PPS4PPS-E45B for Exhaust;
4PPS-E45B for Intake (Direct Vent only)
6” 6PPS-06PVCM-
6PPF PPS-PACL
6PPS-LBC 6PPS-E90 PPS6PPS-E45 for Exhaust;
6PPS-E45 for Intake (Direct Vent only)
TABLE 9
Centrotherm InnoFlue SW Vent system part numbers
Nominal Pipe  Diameter Flue Outlet 
Adapter Adapter Connector Ring 
Connector 90 Degree Elbow
Vent Material Vent Terminal(s)
4” ISAGL 0404 IAFC04IANS04ISEL0487 Polypropylene ISELL0445UV for Exhaust;
ISELL0445UV for Intake (Direct Vent  only)
6” ISAGL 0606 IAFC06IANS06ISEL0687 Polypropylene ISELL0645UV for Exhaust;
ISELL0645UV for Intake (Direct Vent  only) 
						

							28
AL29-4C® VENT INSTALLATIONS
(AL29-4C® is a registered trademark of Allegheny Technologies, Inc.)
The  water  heaters  covered  by  this  manual  are  approved  to  be  installed  with  AL29-4C®  stainless  steel  vent  material  using  parts 
from the manufacturers listed in Table 10 and Table 11 below. These listed systems must be installed using the vent manufacturer’s 
instructions  including  their  listed  clearances  to  combustible  and  noncombustible  materials.  Refer  to  Table  7-PVC/CPVC  and 
Polypropylene on page 22 for the maximum and minimum equivalent linear vent lengths and number of elbows that may be used. 
However, use Table 10 and Table 11 below to find the appropriate equivalent linear vent lengths for the AL29-4C® elbows.
Note: The  equivalent  lengths  of  the AL29-4C®  elbows  are  different  than  those  from  smooth  walled  plastic  vents.  Consult Table  10 
and Table 11 for the correct equivalent linear vent lengths.
Listed vent systems composed of AL29-4C® must not mix parts from the different manufacturers. The joints of these products are 
sealed by internal gaskets. Do not use any other type of sealant. When assembling these vent systems, follow the vent manufacturer’s 
instructions for cleaning and lubricating the joints, if required. Each section must be locked together using the method supplied by 
the vent manufacturer. 
The water heaters covered by this manual are approved to be installed using the approved vent terminations shown in this manual. 
This means that, the installer must use the adapter listed in Table 10 and Table 11 and a short piece of PVC pipe to complete the end 
of the vent system with an approved termination. In Canada, the PVC pipe length must be listed to ULC636.
TABLE 10
HeatFab Saf–T Vent AL29-4C® Vent System Parts
Diameter Flue Outlet 
Adapter *Straight Pipe (3’ 
Section) 45° ElbowEquivalent Linear 
Length, 45° Elbow 90° Elbow
Equivalent Linear 
length, 90° Elbow Adapter to PVC
4" 9401 PVC 9307 94115 feet 941410 feet9454CPVC
6" 9601 PVC 960796115 feet 961410 feet9656CPVC
*Consult vent manufacturer’s catalog for other available lengths.
TABLE 11
Duravent FasNSeal AL29-4C® Vent System Parts
Diameter Flue Outlet 
Adapter *Straight Pipe (3’ 
Section) 45° ElbowEquivalent Linear 
Length, 45° Elbow 90° elbowEquivalent Linear 
Length, 90° Elbow Adapter to PVC
4" 810005545 FSVL3604FSELB4504 5 feetFSELB9004 10 feet810009529
6" 810005225 FSVL3606FSELB4506 5 feetFSELB9006 10 feet81005572 
*Consult vent manufacturer’s catalog for other available lengths.  
						

							29
termination  caps  for  all  concentric  terminations  must 
be  at  the  same  height  measured  from  ground.  See 
Multiple  Concentric  Termination  Arrangements  on 
page 31.
9.  Determine  if  the  concentric  termination  will  need  to  be 
shortened  to  accommadate  required  clearances  or 
to  ensure  all  vent  caps  are  at  the  same  height  when 
installing multiple terminations vertically through the roof 
in the same location.
See Figure 25 for the minimum lengths allowed for the 6 inch 
concentric termination.
Note:  When shortening the length of the termination carefully 
measure  and  cut  the  larger  (intake  air)  pipe  first.  Cut 
the same amount of pipe off of the smaller (vent) pipe.
Note:  Lengthening of the Concentric Vent Termination is not 
permitted.
CONCENTRIC  TERMINATION(S)
MUST  BE A MINIMUM OF 10 FEET
(3 m)  AWAY FROM  ANY PA RAPET,
VER TICAL WA LL OR 
STRUCTURE.
6 INCH CONCENTRIC TERMINA TION
FLA T ROOF CLEARANCE
Figure 24
CONCENTRIC TERMINATION INSTALLATION
1. Concentric terminations must be ordered separately. (A)
HCG3  119T300/400/500  models  must  use  the  6  inch 
concentric  termination  for  both  4"  &  6"  vent  diameters; 
Part Number: 9008841005. Contact your local distributor 
or  call  the  parts  department  phone  number  on  the  back 
cover of this manual to order concentric terminations.
2.  Determine the location for the termination.
NOTE:  Roof  termination  is  preferred  since  it  is  less 
susceptible  to  damage,  has  reduced  chances  to  intake 
contaminants and vent vapors are less visible.
3.  When  installing  a  concentric  termination  vertically 
through the roof; ensure that all exterior vertical clearance 
requirements  for  the  concentric  termination,  shown  in 
Figure  24  on  page  29  and  Figure  26  on  page  30,  are 
being  maintained.  These  clearances  and  those  cited  by 
local and national codes must be maintained.
4.  When  installing  a  concentric  termination  vertically 
through  a  flat  roof,  the  termination's  vent  cap  must  be  a 
minimum of 10 feet (3 m) away from any parapet, vertical 
wall or structure as shown in Figure 24. 
NOTE: If this required distance to a parapet, vertical wall 
or structure cannot be maintained, standard terminations 
must  be  used.  See  Vertical  Termination  Installation  on 
page 24.
5.  When  installing  a  concentric  termination  through  a 
sidewall;  ensure  that  all  exterior  sidewall  clearance 
requirements  for  the  termination,  shown  in  Figure  45b 
on  page  37,  are  being  maintained.  These  clearances 
and  those  cited  by  local  and  national  codes  must  be 
maintained.
6.  When installing multiple concentric terminations vertically 
through  a  roof  or  horizontally  through  a  sidewall  ensure 
the  required  clearances  between  terminations  and 
groupings  of  multiple  terminations  are  maintained.  See 
pages 31 and 32 for more information.
7.  Cut a 7 inch (18 cm) diameter hole for 6 inch concentric 
terminations where they will pass through the wall or roof.
NOTE:  Beware  of  concealed  wiring  and  piping  when 
cutting through the wall or roof.
8.  When  installing  multiple  concentric  terminations 
vertically  through  the  roof  in  the  same  location  the   
						

							30
6 INCH CONCENTRIC TERMINATION INSTALLATION
6 INCH CONCENTRIC TERMINATION KITFIELD ASSEMBL Y REQUIRED
VENT PIPE
INT
AKE  AIR CONNECTION
VENT  CONNECTION - 4 INCH PVC
INTAKE  AIR PIPE
Y FITTING  ASSEMBLY
VENT  CAP
VENT  PIPE  ASSEMBL Y
VENT
 PIPE IS 4 INCH SDR-26 PIPE
SUPPLIED LENGTH 46.50” (1 18 cm)
MINIMUM  ALLOWABLE LENGTH 16.38” (41.6 cm)
INT AKE  AIR PIPE IS 6 INCH SDR-26 PIPE
SUPPLIED LENGTH 25.38” (64.5 cm )
MINIMUM  ALLOWABLE LENGTH 12” (30 cm )VENT
 CAP
INT
AKE  AIR PIPE
6” x 6” x 6”
Y FITTIN G
6” x 4” BUSHING
(FACTO RY
INST ALLED)
Figure 25
Assemble and install the 6 inch concentric termination. Refer to 
Figure 25, Figure 26 and Figure 27 for these instructions:
1.  Cement the Y fitting to the larger diameter intake air pipe.
2.  Slide the intake air pipe and Y fitting assembly from inside the 
building  through  the  hole  cut  for  the  termination  in  the  roof 
or  sidewall.  Ensure  no  foreign  materials  such  as  insulation 
accumulate inside the assembly.
3.  Secure  the  intake  air  Y  fitting  assembly  using  field  supplied 
metal strapping or equivalent support materials.
4.  On  installations  installed  through  the  roof  slide  a  field 
supplied plumbing boot or roof flashing over the intake air Y 
fitting assembly and secure it to the roof.
5.  Seal around the plumbing boot or roof flashing.
6.  Cement  the  vent  cap  onto  the  vent  pipe. Alternately  a  field-
supplied  stainless  steel  screw  may  be  used  to  secure  the  2 
components  together  when  field  disassembly  is  desired  for 
cleaning. A pilot hole must be drilled for the screw to prevent 
damage/cracking of the vent cap and/or vent pipe.
7.  Install  the  vent  cap/vent  pipe  assembly  into  the  intake  air  Y 
fitting assembly, Ensure small diameter vent pipe is cemented 
and bottomed in the Y fitting.
8.  Connect the intake air and vent piping from the water heater  to the 6 inch concentric termination using field supplied 6” x 
4” reducer couplings as needed.
9.  Return  to  Direct  Vent  Installation  on  page  23  to  complete 
the installation of the intake air and vent piping between the 
concentric termination and the water heater.
NOTE: SECURING STRAP  
MUST  BE FIELD INST ALLED 
TO  PREVENT MOVEMENT 
OF  TERMINA TION KIT
MAINT
AIN 12” (30 cm)
18” (45 cm) FOR CANADA
MINIMUM CLEARANCE
ABOVE HIGHEST  ANTICIPAT ED
SNOW LEVEL. MAXIMUM OF
24” (60 cm)  ABOVE ROOF .
ROOF FLASHING
(field supplied) STRAP
(field supplied)
VENT PIPE INT
AKE
AIR PIPE
COMBUSTION
AIR VENT
6 INCH CONCENTRIC 
TERMINATION
VER TICAL  INSTALLATION
Figure 26
NOTE: SECURING STRAP  MUST BE
FIELD INST ALLED TO PREVENT
MOVEMENT  OF TERMINA TION KIT
IN SIDEW ALL.
STRAP
(field supplied)
VENT
PIPE
INT AKE
AIR PIPE COMBUSTION
AIR
VENT
1 INCH
MAXIMUM
6 INCH CONCENTRIC  TERMINATION
SIDEW ALL INST ALLATION
Figure 27