American Water Heater Heavy Duty Commercial Gas BCG3 User Manual

							11
INSULATION BLANKET
Do not obstruct water heater air intake
with insulating blanket.
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
Insulation blankets are available to the general public for external 
use  on  gas  water  heaters  but  are  not  necessary  with  these 
products.  The  purpose  of  an  insulation  blanket  is  to  reduce  the 
standby  heat  loss  encountered  with  storage  tank  heaters.  The 
water heaters covered by this manual meet or exceed the Energy 
Policy Act  standards  with  respect  to  insulation  and  standby  heat 
loss requirements, making an insulation blanket unnecessary.
Should  you  choose  to  apply  an  insulation  blanket  to  this 
heater,  you  should  follow  these  instructions.  See  the  Features 
and  Components  section  of  this  manual  for  identification  of 
components mentioned below. Failure to follow these instructions 
can restrict the air flow required for proper combustion, potentially 
resulting in fire, asphyxiation, serious personal injury or death.
• DO NOT  apply  insulation  to  the  top  of  the  water  heater,  as 
this will interfere with safe operation of the draft hood.
•  DO NOT  cover  the  gas  control  valve,  thermostat  or  the 
Temperature-Pressure Relief Valve.
•  DO NOT  allow  insulation  to  come  within  2”  (5  cm)  of  the 
burners,  to  prevent  blockage  of  combustion  air  flow  to  the 
burners.
•  DO NOT  allow  insulation  to  come  within  9  inches  (23  cm) 
of floor, (within 2 inches (5 cm) of bottom cover) to prevent 
blockage of combustion air flow to the burners..
•  DO NOT cover the instruction manual. Keep it on the side of 
the water heater or nearby for future reference.
•  DO  obtain  new  warning  and  instruction  labels  from  the 
manufacturer for placement on the blanket directly over the 
existing labels.
•  DO inspect the insulation blanket frequently to make certain 
it does not sag, thereby obstructing combustion air flow.
HARD WATER      
Where  hard  water  conditions  exist,  water  softening  or  the 
threshold  type  of  water  treatment  is  recommended.  This  will 
protect the dishwashers, coffee urns, water heaters, water piping 
and other equipment.
See  the  Maintenance  Section  in  this  manual  for  sediment  and 
lime scale removal procedures.
CIRCULATION PUMPS     
A circulating pump is used when a system requires a circulating 
loop or there is a storage tank used in conjunction with the water 
heater. See Water Piping Diagrams in this manual for installation 
location of circulating pumps.
See  the  Circulation  Pump  Wiring  Diagrams  in  this  manual  for 
electrical  hookup  information.  Install  in  accordance  with  the 
current  edition  of  the  National  Electrical  Code,  NFPA  70  or  the 
Canadian Electrical Code, CSA C22.1.
All-bronze  circulating  pumps  are  recommended  for  used  with 
commercial water heaters.
Some circulating pumps are manufactured with sealed bearings 
and  do  not  require  further  lubrication.  Some  circulating  pumps 
FIGURE 6.
NSF LEG KIT
The  NSF  Leg  Kit  (part  number  9003425205)  is  needed  only 
for  applications  that  must  conform  to  NSF/ANSI  Standard  5. 
Installation of the NSF leg kit will increase the height of the unit 
and all connection points by 3 inches. See Figure 7. 
Follow these steps to install the Leg Kit:
1. Unit needs to be lifted in a way not to damage unit or laid on 
it’s side to access the bottom of the legs.
2.  Slide  leg  extension  under  leg  and  the  bolt  up  through  the 
bottom hole located in the bottom of the leg.
3.  Once in place, screw nut down and secure.
4.  Front  of  leg  should  line  up  with  front  of  leg  extension  as 
shown to make sure weight of unit is distributed through the 
leg extension.
FIGURE 7. 
						

							12
Breathing Hazard - Carbon Monoxide Gas
Breathing carbon  monoxide can cause brain  damage or
death.  Always read and understand  instruction  manual. Under no circumstances should
the input exceed the rate shown
on the water heater
’s rating label.  
Overfiring could result in damage to
the water heater and sooting.
Gas and carbon monoxide detectors
are available.
Installations  above  2000  feet  (610  meters)  require 
replacement  of  burner  orifices  in  accordance  with  current 
edition  of  the  National  Fuel  Gas  Code  (ANSI  Z223.1).  For 
Canadian  installations  consult  Canadian  Installations  Code 
CAN/CSA  B149.1.  Failure  to  replace  orifices  will  result  in 
improper and inefficient operation of the water heater resulting 
in the production of increased levels of carbon monoxide gas 
in excess of safe limits which could result in serious personal 
injury or death.
Yo u  s h o u l d  c o n t a c t  y o u r  g a s  s u p p l i e r  f o r  a n y  s p e c i f i c  c h a n g e s  
which may be required in your area.
As  the  elevation  above  sea  level  is  increased,  there  is  less 
oxygen per cubic foot of air. Therefore, the heater input rate 
should be reduced at high altitudes for satisfactory operation 
w i t h  t h e  r e d u c e d  o x y g e n  s u p p l y .  F a i l u r e  t o  m a k e  t h i s  r e d u c t i o n  
would  result  in  an  over  firing  of  the  heater  causing  sooting, 
poor combustion and/or unsatisfactory heater performance.
Ratings specified by manufacturers for most appliances apply 
for  elevations  up  to  2000  feet  (610m).  For  elevations  above 
2000  feet  (610),  ratings  must  be  reduced  at  the  rate  of  4% 
for each 1000 feet (305m) above sea level. For example, if a 
heater is rated at 78,000 Btuh (22.9 Kwh) at sea level, to rate 
the heater at 4000 feet (1219m), you subtract 4 (once for each 
thousand  feet)  x.04  (4%  input  reduction)  x  78,000  (original 
rating) from the original rating.
Therefore,  to  calculate  the  input  rating  at  4,000  feet  (1219m): 
4  x  .04  x  78,000  =  12,480  Btuh  (3.7  Kwh),  78,000  (22.9  Kwh)  - 
12 , 4 8 0  (3 .7  Kw h)  =  6 5 , 5 2 0  B t u h  (19 . 2  Kw h) .  A t  6 0 0 0  f e e t  (18 2 9 m)  
the correct input rating should be 59,280 Btuh (17.4 Kwh).
must  be  periodically  oiled.  Refer  to  the  pump  manufacturer’s 
instructions for lubrication requirements.
CIRCULA TING PUMP  WIRING DIAGRAM
ST ORAGE  TA NK OR BUILDING RECIRCULA TION
FIELD SUPPLIED TEMPERATURE CONTROL
INST ALLED IN  THE STORAGE  TA NK
OR CIRCULA TING LOOP RETURN LINE
CIRC
PUMP
MOT OR
L1 HOT
L2 NEUTRAL 120 V
AC
POWER
CIRCULA TING PUMP  WIRING DIAGRAM
DISHW ASHER LOOP  WITH TOGGLE SWITCH
FIELD SUPPLIED  TEMPERATURE
CONTROL  INSTALLED IN  THE
CIRCULA TING LOOP  RETURN LINE
DISHW
ASHER
T OGGLE
SWITCH
CIRC
PUMP
MOT OR
L1 HOT
L2 NEUTRAL 120 V
AC
POWER
NOTE: USE SEPARATE 120 VAC POWER
SUPPLY  FOR PUMP CIRCUIT . DO NOT
SHARE POWER WITH WATER HEATER AS THIS
MAY  CAUSE ELECTRICAL LINE NOISE AND
LEAD T O ERRATIC CONTROL  SYSTEM
OPERATION. 
NOTE: USE SEPARATE 120 VAC POWERSUPPLY FOR PUMP CIRCUIT. DO NOT SHARE 
POWER WITH WATER HEATER AS THIS MAY 
CAUSE ELECTRICAL LINE NOISE AND LEAD TO ERRATIC CONTROL SYSTEM OPERATION. 
FIGURE 8.
CIRCULA TING PUMP  WIRING DIAGRAM
ST ORAGE  TA NK OR BUILDING RECIRCULA TION
FIELD SUPPLIED TEMPERATURE CONTROL
INST ALLED IN  THE STORAGE  TA NK
OR CIRCULA TING LOOP RETURN LINE
CIRC
PUMP
MOT OR
L1 HOT
L2 NEUTRAL 120 V
AC
POWER
CIRCULA TING PUMP  WIRING DIAGRAM
DISHW ASHER LOOP  WITH TOGGLE SWITCH
FIELD SUPPLIED  TEMPERATURE
CONTROL  INSTALLED IN  THE
CIRCULA TING LOOP  RETURN LINE
DISHW
ASHER
T OGGLE
SWITCH
CIRC
PUMP
MOT OR
L1 HOT
L2 NEUTRAL 120 V
AC
POWER
NOTE: USE SEPARATE 120 VAC POWER
SUPPLY  FOR PUMP CIRCUIT . DO NOT
SHARE POWER WITH WATER HEATER AS THIS
MAY  CAUSE ELECTRICAL LINE NOISE AND
LEAD T O ERRATIC CONTROL  SYSTEM
OPERATION. 
NOTE: USE SEPARATE 120 VAC POWERSUPPLY FOR PUMP CIRCUIT. DO NOT SHARE 
POWER WITH WATER HEATER AS THIS MAY 
CAUSE ELECTRICAL LINE NOISE AND LEAD TO ERRATIC CONTROL SYSTEM OPERATION. 
FIGURE 9.
HIGH ALTITUDE INSTALLATIONS
Fire and Explosion Hazar d
Gas and carbon monoxide detectors ar e
available.
Overfiring could result in fire or
explosion. Under no circumstances should the 
input exceed the rate shown on the 
water heater ’s rating label.   
						

							13
4. When  installing  multiple  water  heaters  in  the  same  gas  supply  
  system  it  is  recommended  that  individual  positive  lock-up  gas  
  pressure regulators be installed at each unit.
POWER SUPPLY
The  water  heaters  covered  in  this  manual  require  a  120  VAC, 
1Ø  (single  phase),  60Hz,  15  amp  power  supply  and  must  also 
be  electrically  grounded  in  accordance  with  local  codes  or,  in  the 
absence  of  local  codes,  with  the  National  Electrical  Code,  ANSI/
NFPA 70 or the Canadian Electrical Code, CSA C22.1.
WATER TEMPERATURE CONTROL AND MIXING VALVES
Wa ter temperature over 125°F (52°C)
can cause severe burns instantly
resulting in severe injury or death.
Children, the elderly and th e
physically or mentally disabled are at
highest risk for scald injur y.
Feel water before bathing or showering.
Te mperature limiting devices such as
mixing valves must be installe d
when required by codes and to
ensure safe temperatures at fixtures .
Water heated to a temperature which will satisfy clothes washing, dish 
washing, and other sanitizing needs can scald and cause permanent 
injury upon contact. Short repeated heating cycles caused by small 
hot water uses can cause temperatures at the point of use to exceed 
the water heater’s temperature setting by up to 20°F (11°C).
Some  people  are  more  likely  to  be  permanently  injured  by  hot  water 
than  others.  These  include  the  elderly,  children,  the  infirm  and  the 
physically/mentally disabled. Table 5 shows approximate time-to-burn 
relationship for normal adult skin. If anyone using hot water provided 
by  the  water  heater  being  installed  fits  into  one  of  these  groups  or  if 
there is a local code or state law requiring a certain water temperature 
at the point of use, then special precautions must be taken.
In  addition  to  using  the  lowest  possible  temperature  setting  that 
satisfies  the  demand  of  the  application  a  Mixing  Valve  should  be 
installed at the water heater (see Figure 10) or at the hot water taps 
to further reduce system water temperature.
Mixing  valves  are  available  at  plumbing  supply  stores.  Consult  a 
Qualified Installer or Service Agency. Follow mixing valve manufacturer’s instructions for installation of the valves.
TABLE 5.
Water Temperature °F Time for 1st Degree Burn
(Less Severe Burns) Time for Permanent Burns2nd & 3rd Degree
(Most Severe Burns)
11 0
(normal shower temp.)
11 6 (pain threshold)
11 6 35 minutes 45 minutes
122 1 minute 5 minutes
131 5 seconds 25 seconds
140 2 seconds 5 seconds
149 1 second 2 seconds
154 instantaneous 1 second
(U.S. Government Memorandum, C.P.S.C., Peter L. Armstrong, Sept. 15,1978)
GAS SUPPLY SYSTEMS
Low pressure building gas supply systems are defined as those 
systems  that  cannot  under  any  circumstances  exceed  14” 
W.C.  (1/2  PSI  Gauge).  These  systems  do  not  require  pressure 
regulation.  Measurements  should  be  taken  to  insure  that  gas 
pressures  are  stable  and  fall  within  the  requirements  stated  on 
the  water  heater  rating  plate.    Readings  should  be  taken  with 
all  gas  burning  equipment  off  (static  pressure)  and  with  all  gas 
burning equipment running at maximum rate (dynamic pressure). 
The  gas  supply  pressure  must  be  stable  within  1.5”  W.C. 
from  static  to  dynamic  pressure  to  provide  good  performance. 
Pressure drops that exceed 1.5” W.C. may cause rough starting, 
noisy  combustion  or  nuisance  outages.  Increases  or  spikes 
in  static  pressure  during  off  cycles  may  cause  failure  to  ignite 
or  in  severe  cases  damage  to  appliance  gas  valves.  If  your 
low  pressure  system  does  NOT  meet  these  requirements,  the 
installer is responsible for the corrections.
High  Pressure  building  supply  systems  use  pressures  that 
exceed 14” W.C. (1/2 PSI Gauge). These systems must use field 
supplied  regulators  to  lower  the  gas  pressure  to  less  than  14” 
W.C. (1/2 PSI Gauge). Water heaters require gas regulators that 
are properly sized for the water heater input and deliver the rating 
plate  specified  pressures.    Gas  supply  systems  where  pressure 
exceeds 5 PSI often require multiple regulators to achieve desired 
pressures.  Systems in excess of 5 PSI building pressure should 
be  designed  by  gas  delivery  professionals  for  best  performance. 
Water heaters connected to gas supply systems that exceed 14” 
W.C.  (1/2  PSI  Gauge)  at  any  time  must  be  equipped  with  a  gas 
supply regulator.  
All models require a minimum gas supply pressure of 4.5" W.C. for 
natural gas and 11.0" W.C. for propane gas. The minimum supply 
pressure  is  measured  while  gas  is  flowing  (dynamic  pressure). 
The supply pressure should never fall below 4.5" W.C. for natural 
gas and 11.0" W.C. for propane gas. The supply pressure should 
be  measured  with  all  gas  fired  appliances  connected  to  the 
common  main  firing  at  full  capacity.  If  the  supply  pressure  drops 
more  than  1.5”  W.C.  as  gas  begins  to  flow  to  the  water  heater 
then  the  supply  gas  system  including  the  gas  line  and/or  the 
gas  regulator  may  be  restricted  or  undersized.  See  Supply  Gas 
Regulator section and Gas Piping section of this manual. The gas 
valve on all models has a maximum gas supply pressure limit of 
14” W.C. The maximum supply pressure is measured while gas is 
not flowing (static pressure).
SUPPLY GAS REGULATOR
The  maximum  allowable  gas  supply  pressure  for  this  water  heater 
is 14 inches W.C. (3.48 kPa). Install a positive lock-up gas pressure 
regulator  in  the  gas  supply  line  if  inlet  gas  pressure  can  exceed  14 
inches W.C. (3.48 kPa) at any time. Regulators must be sized/used 
according to manufacturer’s specifications.
If a positive lock-up regulator is required follow these instructions:
1. Positive lock-up gas pressure regulators must be rated at or above  
  the  input  Btu/hr  rating  of  the  water  heater  they  supply.
2.  Positive lock-up gas pressure regulator(s) should be installed no closer  than  3  equivalent  feet  (1 meter)  and  no  farther  than  8  equivalent  
  feet  (2.4  meters)  from  water  heater’s  inlet  gas  connection.
3.  After  installing  the  positive  lock-up  gas  pressure  regulator(s)  an  
  initial  nominal  supply  pressure  setting  of  7.0”  W.C.  while  the  water  
  heater is operating is recommended and will generally provide good  
  water heater operation. Some addition adjustment maybe required  
  later  to  maintain  a  steady  gas  supply  pressure.
INSTALLATION REQUIREMENTS  
						

							14
HOT WATER
OUTLET
TO TA NK
INLET
CHECK
VA LVE MIXING
VA LVE
COLD
WA TER
INLET TEMPERED WA
TER
OUTLET
12”  TO 15”
(30-38 cm)
CHECK VA LVE
FIGURE 10.
DISHWASHING MACHINES
All  dishwashing  machines  meeting  the  National  Sanitation 
Foundation requirements are designed to operate with water flow 
pressures  between  15  and  25  pounds  per  square  inch  (103  kPa 
and  173  kPa).  Flow  pressures  above  25  pounds  per  square  inch 
(173  kPa),  or  below  15  pounds  per  square  inch  (103  kPa),  will 
result  in  improperly  sanitized  dishes.  Where  pressures  are  high, 
a water pressure reducing or flow regulating control valve should 
be used in the 180°F (82°C) line to the dishwashing machine and 
should be adjusted to deliver water pressure between these limits.
The National Sanitation Foundation also recommends circulation 
of  180°F  (82°C)  water.  The  circulation  flow  rate  should  be  just 
enough to provide 180°F (82°C) water at the point of take-off to 
the dishwashing machine. 
Adjust  flow  by  throttling  a  full  port  ball  valve  installed  in  the 
circulating line on the outlet side of the pump. Never throttle flow 
on  the  suction  side  of  a  pump.  See  Water  Piping  Diagrams  in 
this manual.
NOTE:   These  water  heaters  meet  the  NSF  Standard  5  for 
sanitary installations when used with the leg kit part number 
9003425205.
CLOSED WATER SYSTEMS
Water  supply  systems  may,  because  of  code  requirements 
or  such  conditions  as  high  line  pressure,  among  others,  have 
installed  devices  such  as  pressure  reducing  valves,  check 
valves, and back flow preventers. Devices such as these cause 
the water system to be a closed system.
THERMAL EXPANSION
As water is heated, it expands (thermal expansion). In a closed 
system  the  volume  of  water  will  grow  when  it  is  heated. As  the 
volume  of  water  grows  there  will  be  a  corresponding  increase 
in water pressure due to thermal expansion. Thermal expansion 
can  cause  premature  tank  failure  (leakage).  This  type  of  failure 
is  not  covered  under  the  limited  warranty.  Thermal  expansion 
can  also  cause  intermittent  Temperature-Pressure  Relief  Valve 
operation:  water  discharged  from  the  valve  due  to  excessive 
pressure build up. This condition is not covered under the limited 
warranty. The Temperature-Pressure Relief Valve is not intended 
for the constant relief of thermal expansion.
A  properly  sized  thermal  expansion  tank  must  be  installed  on 
all  closed  systems  to  control  the  harmful  effects  of  thermal 
expansion. Contact a local plumbing service technician to have a 
thermal expansion tank installed.
See  Water  Line  Connections  on  page  21  and  the  Water  Piping 
Diagrams beginning on page 40.
TEMPERATURE-PRESSURE RELIEF VALVE
Explosion Hazard
Te mperature-Pressure Relief  Valve
must comply with  ANSI Z21.22-
CSA 4.4 and  ASME code.
Properly sized temperature-
pressure relief valve must be
installed in opening provided.
Can result in overheating and
excessive tank pressure .
Can cause serious injury or death.
This water heater is provided with a properly rated/sized and certified 
combination  Temperature-Pressure  Relief  Valve  (T&P  valve)  by 
the  manufacturer.  The  valve  is  certified  by  a  nationally  recognized 
testing  laboratory  that  maintains  periodic  inspection  of  production 
of  listed  equipment  of  materials  as  meeting  the  requirements  for 
Pressure Relief Valves for Hot Water Supply Systems, ANSI Z21.22 
• CSA 4.4, and the code requirements of ASME.
If  replaced,  the  new  T&P  valve  must  meet  the  requirements 
of  local  codes,  but  not  less  than  a  combination  Temperature-
Pressure  Relief  Valve  rated/sized  and  certified  as  indicated  in 
the  above  paragraph.  The  new  valve  must  be  marked  with  a 
maximum  set  pressure  not  to  exceed  the  marked  hydrostatic 
working pressure of the water heater (150 psi = 1,035 kPa) and 
a discharge capacity not less than the water heater Btu/hr or kW 
input rate as shown on the water heater’s model rating label.
NOTE: In addition to the factory installed Temperature-Pressure 
Relief Valve on the water heater, each remote storage tank that 
may be installed and piped to a water heating appliance must also 
have  its  own  properly  sized,  rated  and  approved  Temperature-
Pressure  Relief  Valve  installed.  Call  the  toll  free  technical 
support  phone  number  listed  on  the  back  cover  of  this  manual 
for technical assistance in sizing a Temperature-Pressure Relief 
Valve for remote storage tanks.
For safe operation of the water heater, the Temperature-Pressure 
Relief  Valve  must  not  be  removed  from  its  designated  opening 
nor  plugged.  The  Temperature-Pressure  Relief  Valve  must  be 
installed  directly  into  the  fitting  of  the  water  heater  designed  for 
the  pressure  relief  valve  .  Install  discharge  piping  so  that  any 
discharge  will  exit  the  pipe  within  6  inches  (15.2  cm)  above  an 
adequate floor drain, or external to the building. In cold climates 
it  is  recommended  that  it  be  terminated  at  an  adequate  drain 
inside  the  building.  Be  certain  that  no  contact  is  made  with  any 
live  electrical  part.  The  discharge  opening  must  not  be  blocked 
or  reduced  in  size  under  any  circumstances.  Excessive  length, 
over 30 feet (9.14 m), or use of more than four elbows can cause 
restriction and reduce the discharge capacity of the valve.  
						

							15
No  valve  or  other  obstruction  is  to  be  placed  between  the 
Temperature-Pressure Relief Valve and the tank. Do not connect 
discharge  piping  directly  to  the  drain  unless  a  6”  (15.2  cm) 
air  gap  is  provided.  To  prevent  bodily  injury,  hazard  to  life,  or 
property  damage,  the  relief  valve  must  be  allowed  to  discharge 
water  in  adequate  quantities  should  circumstances  demand.  If 
the  discharge  pipe  is  not  connected  to  a  drain  or  other  suitable 
means, the water flow may cause property damage.
Water Damage Hazard
Temperature-Pressure Relief V alve discharge
pipe must terminate at adequate drain.
CAUTION
T&P Valve Discharge Pipe Requirements:
•  Shall not be smaller in size than the outlet pipe size of the 
valve, or have any reducing couplings or other restrictions.
•  Shall not be plugged or blocked.
•  Shall not be exposed to freezing temperatures.
•  Shall be of material listed for hot water distribution.
•  Shall be installed so as to allow complete drainage of both 
the Temperature-Pressure Relief Valve and the discharge 
pipe.
•  Must terminate a maximum of six inches above a floor 
drain or external to the building. In cold climates, it is 
recommended that the discharge pipe be terminated at an 
adequate drain inside the building.
•  Shall not have any valve or other obstruction between the 
pressure relief valve  and the drain.
Burn hazard.
Hot water discharge. Keep clear of  Temperature-
Pressure Relief V alve
discharge outlet.
The Temperature-Pressure Relief Valve must be manually operated 
at least twice a year. Caution should be taken to ensure that (1) no 
one is in front of or around the outlet of the Temperature-Pressure 
Relief Valve discharge line, and (2) the water manually discharged 
will  not  cause  any  bodily  injury  or  property  damage  because 
the  water  may  be  extremely  hot.  If  after  manually  operating  the 
valve,  it  fails  to  completely  reset  and  continues  to  release  water, 
immediately close the cold water inlet to the water heater, follow the 
draining instructions in this manual, and replace the Temperature-
Pressure Relief Valve with a properly rated/sized new one.
NOTE:  The  purpose  of  a  Temperature-Pressure  Relief  Valve  is  to 
prevent excessive temperatures and pressures in the storage tank. 
The  T&P  valve  is  not  intended  for  the  constant  relief  of  thermal 
expansion.  A  properly  sized  thermal  expansion  tank  must  be 
installed  on  all  closed  systems  to  control  thermal  expansion,  see 
Closed Water Systems and Thermal Expansion on page 14.
If  you  do  not  understand  these  instructions  or  have  any  questions 
regarding  the  Temperature-Pressure  Relief  Valve  call  the  toll 
free  number  listed  on  the  back  cover  of  this  manual  for  technical 
assistance.
CONTAMINATED AIR
Breathing Hazard - Carbon Monoxide Ga s
Install water heater in accordance with
the Instruction Manual and NFPA 54 or
CAN/CSA-B149.1.
To  avoid injur y, combustion and ventilation
air must be taken from outdoors.
Do not place chemical vapor  emitting
products near water heater .
Breathing carbon monoxide can cause brain damage or
death. Always read and understand instruction manual.
Corrosion  of  the  flue  ways  and  vent  system  may  occur  if  air  for 
combustion  contains  certain  chemical  vapors.  Such  corrosion 
may result in failure and risk of asphyxiation.
Combustion air that is contaminated can greatly diminish the life 
span of the water heater and water heater components such as 
hot  surface  igniters  and  burners.  Propellants  of  aerosol  sprays, 
beauty  shop  supplies,  water  softener  chemicals  and  chemicals 
used in dry cleaning processes that are present in the combustion, 
ventilation or ambient air can cause such damage.
Do not store products of this sort near the water heater. Air which 
is brought in contact with the water heater should not contain any 
of  these  chemicals.  If  necessary,  uncontaminated  air  should  be 
obtained  from  remote  or  outdoor  sources.  The  limited  warranty 
is  voided  when  failure  of  water  heater  is  due  to  a  corrosive 
atmosphere.  (See  limited  warranty  for  complete  terms  and 
conditions).
AIR REQUIREMENTS
Breathing Hazard - Carbon Monoxide Ga s
Install water heater in accordance with
the Instruction Manual and NFPA 54 or
CAN/CSA-B149.1.
To  avoid injur y, combustion and ventilation
air must be taken from outdoors.
Do not place chemical vapor  emitting
products near water heater .
Breathing carbon monoxide can cause brain damage or
death. Always read and understand instruction manual.
For safe operation an adequate supply of fresh uncontaminated 
air for combustion and ventilation must be provided.
An insufficient supply of air can cause recirculation of combustion 
products  resulting  in  contamination  that  may  be  hazardous  to 
life. Such a condition often will result in a yellow, luminous burner 
flame, causing sooting of the combustion chamber, burners and 
flue tubes and creates a risk of asphyxiation.
Do  not  install  the  water  heater  in  a  confined  space  unless  an 
adequate supply of air for combustion and ventilation is brought 
in  to  that  space  using  the  methods  described  in  the  Confined 
Space section that follows.
Never obstruct the flow of ventilation air. If you have any doubts 
or  questions  at  all,  call  your  gas  supplier.  Failure  to  provide  the 
proper amount of combustion air can result in a fire or explosion 
and cause property damage, serious bodily injury or death.  
						

							16
DIRECT VENT APPLIANCES
Appliances installed in a Direct Vent configuration that derive all 
air for combustion from the outdoor atmosphere through sealed 
intake air piping are not factored in the total appliance input Btu/
hr calculations used to determine the size of openings providing 
fresh air into confined spaces.
EXHAUST FANS
Where exhaust fans are installed, additional air shall be provided 
to  replace  the  exhausted  air.  When  an  exhaust  fan  is  installed 
in  the  same  space  with  a  water  heater,  sufficient  openings  to 
provide  fresh  air  must  be  provided  that  accommodate  the 
requirements for all appliances in the room and the exhaust fan. 
Undersized  openings  will  cause  air  to  be  drawn  into  the  room 
through the water heater’s vent system causing poor combustion. 
Sooting, serious damage to the water heater and the risk of fire 
or explosion may result. It can also create a risk of asphyxiation.
LOUVERS AND GRILLES
The  free  areas  of  the  fresh  air  openings  in  the  instructions  that 
follow do not take in to account the presence of louvers, grilles or 
screens in the openings.
The  required  size  of  openings  for  combustion,  ventilation  and 
dilution air shall be based on the “net free area” of each opening. 
Where the free area through a design of louver or grille or screen 
is  known,  it  shall  be  used  in  calculating  the  size  of  opening 
required to provide the free area specified. Where the louver and 
grille  design  and  free  area  are  not  known,  it  shall  be  assumed 
that wood louvers will have 25% free area and metal louvers and 
grilles will have 75% free area. Non motorized louvers and grilles 
shall be fixed in the open position.UNCONFINED SPACE
An Unconfined Space is one whose volume IS NOT LESS THAN 
50  cubic  feet  per  1,000  Btu/hr  (4.8  cubic  meters  per  kW)  of  the 
total input rating of all appliances installed in the space. Rooms 
communicating  directly  with  the  space,  in  which  the  appliances 
are  installed,  through  openings  not  furnished  with  doors,  are 
considered a part of the unconfined space.
Makeup  air  requirements  for  the  operation  of  exhaust  fans, 
kitchen  ventilation  systems,  clothes  dryers  and  fireplaces  shall 
also  be  considered  in  determining  the  adequacy  of  a  space  to 
provide combustion, ventilation and dilution air.
UNUSUALLY TIGHT CONSTRUCTION
In  unconfined  spaces  in  buildings,  infiltration  may  be  adequate 
to  provide  air  for  combustion,  ventilation  and  dilution  of  flue 
gases.  However,  in  buildings  of  unusually  tight  construction  (for 
example,  weather  stripping,  heavily  insulated,  caulked,  vapor 
barrier,  etc.)  additional  air  must  be  provided  using  the  methods 
described in the Confined Space section that follows.
CONFINED SPACE
A  Confined  Space  is  one  whose  volume  is  less  than  50  cubic 
feet per 1,000 Btu/hr (4.8 cubic meters per kW) of the total input 
rating of all appliances installed in the space.
Openings  must  be  installed  to  provide  fresh  air  for  combustion, 
ventilation and dilution in confined spaces. The required size for 
the openings is dependent on the method used to provide fresh 
air  to  the  confined  space  and  the  total  Btu/hr  input  rating  of  all 
appliances installed in the space.
VENTING INSTALLATION
VENTING
THE  INSTRUCTIONS  IN  THIS  SECTION  ON  VENTING  MUST 
BE  FOLLOWED  TO  AVOID  CHOKED  COMBUSTION  OR 
RECIRCULATION OF FLUE GASES.  SUCH CONDITIONS CAUSE 
SOOTING OR RISKS OF FIRE AND ASPHYXIATION.
Heater must be protected from freezing downdrafts.
Remove all soot or other obstructions from the chimney that will retard 
a free draft.
Type B venting is recommended with these heaters. For typical venting 
application see TECHNICAL DATA VENTING on pages 19 and 20. 
This water heater must be vented in compliance with all local codes, 
the current revision of the National Fuel Gas Code (ANSI-Z223.1) and 
with the Category I Venting Tables.
If any part of the vent system are exposed to ambient temperatures 
below 40°F it must be insulated to prevent condensation.
• Do not connect the heater to a common vent or chimney with solid 
fuel burning equipment.  This practice is prohibited by many local  
building codes as is the practice of venting gas fired equipment to 
the duct work of ventilation systems.
•   Where a separate vent connection is not available and the vent pipe 
from the heater must be connected to a common vent with an oil 
burning  furnace,  the  vent  pipe  should  enter  the  smaller  common 
vent or chimney at a point above the large vent pipe.
VENT REDUCER
Model  BCG370T120  is  shipped  with  a  6"  to  5"  flue  outlet 
adapter.  Models  (A)BCG3100T250,  (A)BCG365T250  and  (A)
BCG3100T275 are shipped with a 8" to 6" flue outlet adapter. Each adapter fits on top of the installed flue damper. Use only vent 
reducers supplied with the unit. The venting must comply with the 
current editions of the NATIONAL FUEL GAS CODE, ANSI Z223.1/
NFPA  54  or  NATURAL  GAS  AND  PROPANE  INSTALLATION 
CODE CAN/CSA-B149.1
FIGURE 11.
FIGURE 12.  
						

							17
MULTIPLE HEATER MANIFOLD
Figure  13  and  tables  on  pages  19  and  20  should  be  used  for 
horizontally manifolding two or more heaters.
FIGURE 13.
FRESH AIR OPENINGS FOR CONFINED SPACES
The  following  instructions  shall  be  used  to  calculate  the  size, 
number  and  placement  of  openings  providing  fresh  air  for 
combustion,  ventilation  and  dilution  in  confined  spaces.  The 
illustrations shown in this section of the manual are a reference 
for  the  openings  that  provide  fresh  air  into  confined  spaces 
only. DO NOT refer to these illustrations for the purpose of vent 
installation.  See  Venting  Installation  on  page  16  for  complete 
venting installation instructions.
OUTDOOR AIR THROUGH TWO OPENINGS
FIGURE 14.
The  confined  space  shall  be  provided  with  two  permanent 
openings, one commencing within 12 inches (300 mm) of the top 
and one commencing within 12 inches (300 mm) of the bottom of 
the enclosure. The openings shall communicate directly with the 
outdoors. See Figure 14.
Each  opening  shall  have  a  minimum  free  area  of  1  square  inch 
per 4,000 Btu/hr (550 mm
2 per kW) of the aggregate input rating 
of  all  appliances  installed  in  the  enclosure.  Each  opening  shall 
not be less than 100 square inches (645 cm
2). 
OUTDOOR AIR THROUGH ONE OPENING
FIGURE 15.
Alternatively a single permanent opening, commencing within 12 
inches  (300  mm)  of  the  top  of  the  enclosure,  shall  be  provided. 
See  Figure  14.  The  water  heater  shall  have  clearances  of  at 
least 1 inch (25 mm) from the sides and back and 6 inches (l50 
mm) from the front of the water heater. The opening shall directly 
communicate with the outdoors or shall communicate through a 
vertical  or  horizontal  duct  to  the  outdoors  or  spaces  that  freely 
communicate  with  the  outdoors  and  shall  have  a  minimum  free 
area of the following:
1.  1  square  inch  per  3000  Btu/hr  (733  mm
2  per  kW)  of  the  total  input  
rating of all appliances located in the enclosure, and
2.  Not less than the sum of the areas of all vent connectors in the space.
OUTDOOR AIR THROUGH TWO HORIZONTAL DUCTS
FIGURE 16.
The  confined  space  shall  be  provided  with  two  permanent 
horizontal ducts, one commencing within 12 inches (300 mm) of 
the  top  and  one  commencing  within  12  inches  (300  mm)  of  the 
bottom of the enclosure. The horizontal ducts shall communicate 
directly with the outdoors. See Figure 16.
Each duct opening shall have a minimum free area of 1 square 
inch per 2,000 Btu/hr (1100 mm
2 per kW) of the aggregate input 
rating of all appliances installed in the enclosure.
When ducts are used, they shall be of the same cross sectional 
area  as  the  free  area  of  the  openings  to  which  they  connect. 
The minimum dimension of rectangular air ducts shall be not less 
than 3 inches.   
						

							18
When ducts are used, they shall be of the same cross sectional 
area  as  the  free  area  of  the  openings  to  which  they  connect. 
The minimum dimension of rectangular air ducts shall be not less 
than 3 inches.
AIR FROM OTHER INDOOR SPACES
FIGURE 18.
The  confined  space  shall  be  provided  with  two  permanent 
openings, one commencing within 12 inches (300 mm) of the top 
and one commencing within 12 inches (300 mm) of the bottom of 
the enclosure. See Figure 18.
Each  opening  shall  communicate  directly  with  an  additional 
room(s)  of  sufficient  volume  so  that  the  combined  volume  of  all 
spaces meets the criteria for an Unconfined Space.
Each  opening  shall  have  a  minimum  free  area  of  1  square  inch 
per 1,000 Btu/hr (2200 mm
2 per kW) of the aggregate input rating 
of  all  appliances  installed  in  the  enclosure.  Each  opening  shall 
not be less than 100 square inches (645 cm
2). 
OUTDOOR AIR THROUGH TWO VERTICAL DUCTS
The  illustrations  shown  in  this  section  of  the  manual  are  a 
reference  for  the  openings  that  provide  fresh  air  into  confined 
spaces only.
DO NOT  refer  to  these  illustrations  for  the  purpose  of  vent 
installation.  See  Venting  Installation  on  page  14  for  complete 
venting installation instructions.
FIGURE 17.
The confined space shall be provided with two permanent vertical 
ducts, one commencing within 12 inches (300 mm) of the top and 
one commencing within 12 inches (300 mm) of the bottom of the 
enclosure. The vertical ducts shall communicate directly with the 
outdoors. See Figure 17.
Each duct opening shall have a minimum free area of 1 square 
inch  per  4,000  Btu/hr  (550  mm
2  per  kW)  of  the  aggregate  input 
rating of all appliances installed in the enclosure.   
						

							19
TYPE B GAS VENT
Multiple Gas Fired Tank-Type Heaters
When venting multiple tank type heaters using Type B vent pipe, 
follow  the  installation  diagram  (Figure  13)  and  tables  below 
which give sizing and data based upon NFPA 54/ANSI Z223.  
TABLE 6. TECHNICAL DATA VENTING
MODEL (A)BCG370T120
Input: 120,000 Btuh                                                     \
                                         Total Vent Height (Feet)Draft Hood: 5” 6810 15203050100
Input Btuh Rise Vent Connector Diameter (inches)
120,000 1 Ft.77 766666
120,000 2 Ft.66 666665
120,000 3 Ft.66 666555
Number of  Heaters Combined Input in 
Thousands of Btuh Manifold and Common Vent Diameter (In inches)
2240
1088777673360 1010 1010 8877
4 480 1212 12101010 88
MODEL (A)BCG380T150
Input: 154,000 Btuh                                                     \
                                                 Total Vent Height (Feet)
Draft Hood: 6” 6810 15203050100
Input Btuh Rise                             Vent Connector Diameter (in inches)
154,000 1 Ft.88 777777
154,000 2 Ft.77 777666
154,000 3 Ft.77 766666
Numbers of  Heaters Combined Input in 
Thousands of Btuh Manifold and Common Vent Diameter (in inches)
2308
1010 10 887773462 1212 12101010 88
4 616 1414 12121210 110
MODEL BCG380T180, BCG3100T199, BCG380T199, & (A)BCG3100T200
Input: 180,000, 199,000 Btuh                                            \
                                         Total Vent Height (Feet) Draft Hood: 6” 6810 15203050100
Input Btuh Rise                             Vent Connector Diameter (in inches)
180,000 1 Ft.88 888777
199,000 -- 888887
180,000 2 Ft.88 777777
199,000 88 887777
180,000 3 Ft.77 777766
199,000 88 777776
Number of  Heaters Combined Input in 
Thousands of Btuh Manifold & Common Vent Diameter
2 360
1010 1010 8877
398 1210 101010 887
3 540
1412 1212101010 8
597 1414 121212101010
4 720
1414 141212121010
796 1614 141412121210  
						

							20