American Water Heater Common Vent Kit for HCG3 Series User Manual

							PRINTED 1015 332199-001
CONTENTS
1. Introduction          
2. PVC Common Vent Kit Instructions (See Page 3)
3. Polypropylene Common Vent Kit Instructions(See Page 9)
COMMON VENT KIT (PVC AND DURAVENT)
Kit Instructions
SERVICING SHOULD ONLY BE PERFORMED BY A QUALIFIED SERVICE TECHNICIAN
0036004800550059004C0046004C0051004A00030056004B00520058004F0047000300520051004F005C000300450048000300530048005500490052005500500048004700030045005C000300440003003400580044004F004C00BF0048004700030036004800550059004C004600480003   
						

							2
INTRODUCTION
These instructions cover how to use the above kits to install two of any combination of the following 150 to 250 
models  or  300  to  500  models  of  water  heaters  in  a  common  horizontal  direct  vent  configuration. You  may  not 
combine water heaters from the two groups:
150 to 250 Models, Series 200/201;
A. O. SMITH MODELS: BTH 150(A), BTH 199(A) & BTH 250(A)
AMERICAN MODELS: (A)HCG3100T 150, (A)HCG3100T 199 & (A)HCG3100T 250
STATE MODELS: SUF 150(N,P)E(A), SUF 199(N,P)E(A) & SUF 250(N,P)E(A)
RELIANCE MODELS: RUF 150(N,P)E(A), RUF 199(N,P)E(A) &  RUF 250(N,P)E(A) Serie\
s 200,201
JOHN WOOD MODELS: (A)JWSH100150(N,P), (A)JWSH100199(N,P) & (A)JWSH100250(N,P)
300 to 500 Models, Series 200/201:
A. O. SMITH MODELS: BTH 300(A,Y,Z), BTH 338(A), BTH 400(A) & BTH 500(A)
AMERICAN MODELS: (A)HCG3119T 300 & (A)HCG3130T 400
STATE MODELS: SUF 300150(N,P)E(A), SUF 400150(N,P)E(A) & SUF 500150(N,P)E(\
A)
RELIANCE MODELS: RUF 300150(N,P)E(A), RUF 400150(N,P)E(A) & RUF 500150(N,P)E(A\
)
JOHN WOOD MODELS: (A)JWSH119300(N,P) & (A)JWSH119400(N,P)
NOTE: These instructions are included with a kit that connects one water heater to a common vent system. Study 
this instruction to determine how many kits you may need for your instal\
lation.
Servicing should only be performed by a 4ualified Service Technician  
						

							3
PVC COMMON VENT KIT 9009152005 OR 9009227005 INSTRUCTIONS
ADDITIONAL INFORMATION
This kit instruction is a supplement to the Instruction Manual that is supplied with the water heater. The multiple 
heater installation must satisfy all the requirements of the Instruction Manual as well as the requirements of this 
kit instruction. The installer may also consult with installation instructions from the vent manufacturer. In the event 
of any conflict between the documents, these instructions take precedence.
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. The 
kit is meant to accommodate heaters that maintain the recommended 24” clearance between the water heaters.
NOTE: The use of cellular core PVC (ASTM F891), cellular core CPVC, or Radel® (polyphenolsulfone) in non-
metallic  venting  system  is  prohibited.  Covering  non-metallic  vent  pipe  and  fittings  with  thermal  insulation  is 
prohibited.
PVC PARTS LIST
Each kit contains the adapters needed to connect the vent and air intake system to one heater. Additional parts 
are needed to create the connectors, common sections and vent terminations. A list of additional parts is included 
below for your convenience. 
For example, to common vent 2 heaters requires 2 of the kits in Table 1A, the additional parts in Table 2, and 
PVC parts selected to fit the installation.
12
ITEM 
NO.
KIT #DESCRIPTIONKIT 
SUPPLIED
1VENT ADAPTER,OUTLET,6,PP,DURAVENT1
2 9009152005
VENT ADAPTER,PP/PVC,STAINLESS,DURAVENT1
3
INSTRUCTION,COMMON VENT KIT,BTH 150-250 (NOT SHOWN)1
TABLE 1A. PVC COMMON VENT KIT (150 TO 250 MODELS) (ONE KIT NEEDED FOR EACH HEATER)
NO.
KIT #DESCRIPTIONKIT 
SUPPLIED
1 1
2BACKFLOW PREVENTER, BTH 300-500, DURAVENT
1VENT ADAPTER, BTH 300-500, SS, DURAVENT9009227005
ITEM
 NO.
TABLE 1B. PVC COMMON VENT KIT (300 TO 500 MODELS) (ONE KIT NEEDED FOR EACH HEATER)
Servicing should only be performed by a 4ualified Service Technician  
						

							4
12
3
ITEM 
NO.
PART 
NUMBERDESCRIPTIONADDITIONALREQUIRED
19005376205PLATE,WALL COVER,0.052,GALV,STEEL4
2
332647-000VENT SCREEN COUPLING ASSEMBLY,62
3
321764-000AIR INTAKE TERMINAL2
TABLE 2. ADDITIONAL REQUIRED PARTS - PVC
Supports - You will need enough supports so that you can install one every 3 feet of horizontal run and every 5 
feet of vertical run for both the inlet and vent pipe. Supports may be field supplied metal strapping or equivalent.
 
Condensate Drain - Each water heater must have a separate condensate drain line running to an open drain. 
Follow the directions in the water heater’s Instruction Manual. Do not use a common condensate drain line for 
multiple heaters.
INSTRUCTIONS
Physical Layout - General
This kit may be used as part of a common vent installation of two of any combination of the models in the 150 to 
250 group or the 300 to 500 group listed on Page 2 of this manual in a horizontal direct vent configuration. You 
may not mix water heaters from the different groups.
NOTE: Do not use these parts to combine these water heaters with any oth\
er heater or gas appliance.
This kit is meant to common vent water heaters that are physically close to each other and facing the same 
direction. The limits of this kit are:
• Two (2) heaters only,
• Both heaters on the same floor,
• Through the wall vent and air inlet terminations,
• Both heaters in the same room (pressure zone),
• No  change  to  the  system  layout,  as  shown  in  Figure 1  or  Figure 4,  except  as  explained  in  the  section 
following and
• The adapters shown in Table 1A and Table 3A must not be modified.
The system layout must be planned to minimize the linear length and number of fittings in the system. The kit is 
meant to accommodate heaters that maintain the recommended 24” clearance between the water heaters, (52” 
on center for the 120 to 250 models and 57” on center for the 300 to 500 models). Consult the water heater’s 
installation instructions for proper clearances for service.  Consult the water heater’s Instruction Manual and see 
Figure 2 for requirements for locating the air intake and vent terminals.
The common vent is the section of the vent and air inlet piping where the gases from both heaters flow together, 
See Figure 1. The maximum equivalent length straight pipe and elbows of the common sections is 50 feet. The 
minimum equivalent length of the common sections is 3 feet. Each  90° elbow is equal to 5 feet and a 45° elbow 
is equal to 2½ feet. The maximum number of elbows is three. The air intake terminal (90° elbow) is not included 
in the equivalent length.
Maximum Equivalent Lengths - The normal maximum equivalent lengths of the system are:
Common section: 50 feet, Connector height: 110” and Heater spacing: 24” clearance (see above).
If it is necessary to modify the connectors or heater spacing, the equivalent length of additional vent connector, 
heater spacing or elbows must be deducted from the 50 equivalent feet of the common vent or common air intake 
sections.
Servicing should only be performed by a 4ualified Service Technician  
						

							5
The  individual  vent  connectors  attach  the  heaters  to  the  common  vent.  The  exhaust  vent  connectors  are  
attached to the water heater with the parts in the kit. The air inlet connectors are attached with PVC reducing  
fittings  to  the  heater’s  PVC  coupling. As  shown  in Figure  1,  the  individual  vent  connectors  consist  of  vertical 
and  horizontal  sections  that  connect  the  heater  outlets  to  the  common  vent.  Using  different  lengths  of  pipes, 
the height of the horizontal sections may be adjusted to be from 80” to 110” from the bottom of the heater to the  
centerline of the horizontal section. The combustion air and exhaust vent sides of the system may be different 
heights, but each must meet the 80” to 110” height requirement.
Support:
DO NOT SUPPORT WEIGHT OF VENT SYSTEM ON THE HEATER. Supports must be installed every 3 feet of 
horizontal run and 5 feet of vertical run for both the inlet and vent pipe. Supports may be made of field supplied 
metal strapping or equivalent. The common vent outlet piping must be sloped upwards toward the vent terminal 
at least 1/4” per foot.
Terminations:
See Figure 2 for location requirements of horizontal vent and intake terminations. You must use the terminations 
found in the additional required parts list. The air inlet terminal is a 90° elbow pointing down and the vent outlet 
is the end of a straight pipe section, facing horizontally.
COMMON VENTING
AIR INTAKE TERMINAL
(FIELD SUPPLIED PARTS, SEE TABLE 2)
6Ø VENT SCREEN
COUPLING ASSEMBLY
(FIELD SUPPLIED PARTS, SEE TABLE 2)
VENT ADAPTER PP/PVC, STAINLESS DURAVENT
(KIT SUPPLIED PARTS) (REFER TO TABLES 1A & 1B  FOR RESPECTIVE MODELS AND KITS)
VENT ADAPTER, OUTLET 6, PP, DURAVENT
(KIT SUPPLIED PARTS) (SEE TABLES 1A & 1B  FOR RESPECTIVE MODELS AND KITS)
INDIVIDUAL VENTCONNECTOR
FIGURE 1. DEFINITION OF SYSTEM SECTIONS - PVC 
Servicing should only be performed by a 4ualified Service Technician  
						

							6
ASSEMBLY:
All  joints  that  are  PVC  to  PVC  should  be  attached  using  approved  solvent  glue.  See  the  water  heater’s  
Instruction Manual for additional details. Start the assembly at the wall termination and proceed towards the 
middle of the common system.  Next, start assembly at the appliances. This will allow small adjustments near 
the tees over the heaters.
Wall Penetration - The general instructions for penetrating the side wall are found in the Side Wall  
Terminations sections of the water heater’s Instruction Manual. The common vent system may not be used with 
the concentric or low  profile vent terminals as described in the Instruction Manual supplied with the water heater.
For each penetration, cut a 7” diameter hole through the structure. First, attach the final terminations for the ex-
haust outlet and air intake to their final, straight pipes. Outside the building, insert the last straight pipe sections 
through the wall plates and then, through the penetration. Run a bead of field-supplied silicone sealant around 
the wall plate and press it in place. Inside the building, place a second wall  plate over each of the pipes and seal 
the plates to the wall with silicone sealant. After the vent system is completely set up, finish the penetrations by 
sealing the gap between the pipe and wall plates with a bead of silicone\
 sealant.
FIGURE 2. WALL TERMINATIONS
Servicing should only be performed by a 4ualified Service Technician  
						

							7
VENT
The  exhaust  vent  is  connected  to  the  heater  by  two  adapters.  The  vent  outlet  adapter/  backflow  preventer  is  
connected  to  the  aluminum  exhaust  vent  elbow  by  inserting  the  male  end  of  the  vent  outlet  adapter  into  the 
outlet and securing it with the rubber boot and hose clamps (supplied with the water heater as shown in Figure 
3). Then, insert the backflow preventer into the adapter. Next, the Polypropylene/ PVC adapter is inserted into 
the outlet of the backflow preventer and secured with the attached locking ring. After that, the remainder of the 
exhaust vent side of the common system is composed of Schedule 40 PVC pipe and fittings.
Straight pipe to tee - Use field-supplied straight pipe sections to reach the horizontal part of the system that runs 
above the heaters. The total height from the bottom of the heater to the centerline of the horizontal must be from 
80” to 110”.
LOCKING RING
FIGURE 3. OUTLET VENT ADAPTER & ADAPTER TO PVC
150 - 250 MODELS300 to 500 MODELS
Servicing should only be performed by a 4ualified Service Technician   
						

							8
INLET AIR SIDE
Adapter  to  inlet  -  The  water  heater’s  air  inlet  is  either  a  3”  or  4”  PVC  coupling.  For  the  150  to  250  models,  
attach  a  3”  to  4”  reducing  adapter  and  then,  a  4”  to  6”  reducing  adapter  to  begin  the  6”  vent  connector.  The 
300 to 500 models require only a 4” to 6” reducing adapter. A 90° elbow is then attached to turn the connector  
vertical, towards the remainder of the system.
Straight pipe to tee - A straight pipe section is used to run from the elbow to the bottom of the tee. The length may 
be adjusted so that the height to the center line of the horizontal run is 80” to 110” from the base of the heater. 
In certain cases, it is desirable to provide a means to drain water from the weather out of the air inlet. The drain 
should be a 6” diameter fitting with a J-trapped drain, such as detailed in the water heater’s Instruction Manual. 
The drain should be placed just before the tee that joins the common section with the connectors (away from 
the heaters).
Common Sections
The common sections are the pipes that carry the vent gas or intake air to and from the outside. Each pipe\
 must 
extend from the tee over the heaters to the outside/ outdoors etc. It is preferred to run the air and vent sections 
next to each other, over a similar path as shown in Figure 1. However, differences may be needed in the field. The  
requirements for both the air intake and vent common sections are:
• The equivalent length straight pipe and elbows of each common section will be limited\
 to between 3 feet 
and 50 feet. Each (3) 90° elbow is equivalent to 5 feet pipe and a 45° elbow is equivalent to 2½ feet of pipe. 
The maximum number of elbows is three. The terminal elbows are not considered in calculating maximum 
or minimum equivalent lengths;
• Each common section may include vertical sections, but the final terminations must be horizontal through the 
wall. Vertical section lengths must be included in the total equivalent length.\
• The horizontal vent section must be sloped upward at least 1/4” per f\
oot towards the vent terminal and
• Each section must be supported as detailed in the above procedure.
Terminations
The placement of the vent and air terminals must follow the guidelines for terminal location found in the water  
heater’s Instruction Manual. All required clearances to building features are the same as found in the water heater’s  
Instruction Manual. The combustion vent terminal is a coupling with a screen that finishes the end of the pipe.  
The air inlet terminal must use the 90° elbow pointed down as shown in Figure 2. Clearances to the ground and 
to anticipated snow level must be as shown in Figure 2. The ends of both terminals must be protected with the 
bird screens supplied with the terminations.
Servicing should only be performed by a 4ualified Service Technician  
						

							9
POLYPROPYLENE COMMON VENT KIT 9009132005 OR 9009226005 INSTRUCTIONS
This kit instruction is a supplement to the Instruction Manual that is supplied with the water heater. The multiple 
heater installation must satisfy all the requirements of the Instruction Manual as well as the requirements of this 
kit instruction. The installer may also consult with installation instructions from the vent manufacturer. In the event 
of any conflict between the documents, these instructions take precedence. The kit is meant to accommodate 
heaters that are 52” apart, on center.
The heaters listed previously may also be common vented using a Polyprop\
ylene system manufactured by M&G 
Duravent. This is a system listed to UL 1738 and ULC S636 and may be required in some localities.
POLYPROPYLENE PARTS LIST
Each kit contains the adapters needed to connect the vent and air intake system to one heater. Additional parts 
are needed to create the connectors, common sections and vent terminations. A list of additional parts is included 
below for your convenience.
For example, to common vent 2 heaters requires 2 of the kits in Table 3A plus the additional parts in Table 4. This 
is enough to create the system in Figure  4. Additional  Polypropylene  parts may be needed  to extend  the pipe 
systems between the heaters and the terminations.
2
1
3
ITEM 
NO.
KIT #
NUMBERDESCRIPTIONKIT 
SUPPLIED 
1VENT ADAPTER,OUTLET,6,PP,DURAVENT1
2
9009132005VENT ADAPTER,INLET,6,PP,DURAVENT1
3
VENT ADAPTER CONNECTOR,DURAVENT1
TABLE 3A. POLYPROPYLENE COMMON VENT KIT (150 - 250 MODELS) (ONE KIT NEEDED FOR EAC\
H HEATER)
ITEM 
NO.
KIT #
NUMBERDESCRIPTIONKIT 
SUPPLIED 
1
APPLIANCE-INCREASER, BTH 300-500, DURAVENT
1
29009226005BACKFLOW PREVENTER, BTH 300-500, DURAVENT1
TABLE 3B. POLYPROPYLENE COMMON VENT KIT (300 - 500 MODELS) (ONE KIT NEEDED FOR EAC\
H HEATER)
Servicing should only be performed by a 4ualified Service Technician  
						

							10
1 24
5
 7
3
UV RESISTANT(BLACK)
UV RESISTANT(BLACK)
 8
NOTES:ITEMS 1 THRU 8 ARE FIELD SUPPLIED ONLY1.LOCKING RINGS ARE PREINSTALLED ON PIPES, TEES, AND ELBOWS2.
ITEM NO.PART NUMBERDURAVENT STOCK NO.DESCRIPTION
ADDITIONALREQUIRED
FOR 2 HEATERS
1       N/A810009776VENT PIPE,6,72,PP,DURAVENT6
2
       N/A810009774VENT PIPE,6,36,PP,UV,DURAVENT2
3
       N/A810009772VENT PIPE,6,12,PP,DURAVENT4
4
       N/A810009787VENT TEE W/CAP,90,6,PP,DURAVENT2
5
       N/A810009783ELBOW,90,6,PP,UV,DURAVENT1
6
       N/A810004276BIRD SCREEN,6,DURAVENT2
 7
       N/A810009782ELBOW,90,6,PP,DURAVENT4
 89005376205N/APLATE,WALL COVER,0.052,GALV,STEEL4
6
TABLE 4. ADDITIONAL REQUIRED PARTS - POLYPROPYLENE
0036004800550059004C0046004C0051004A00030056004B00520058004F0047000300520051004F005C000300450048000300530048005500490052005500500048004700030045005C000300440003003400580044004F004C00BF0048004700030036004800550059004C004600480003