American Water Heater 80 Thermal Efficiency UltraLow NOx Heavy Duty Commercial Gas Water Heater BCL3 User Manual

							11
HIGH ALTITUDE INSTALLATIONS
Fire and Explosion Hazard
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.  
Breathing Hazard - Carbon Monoxide Ga s
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.
Special consideration must be taken with
installations above 10,100’  (3078m) for
standard models.
Gas and carbon monoxide detectors are
available.
The  water  heaters  covered  by  this  manual  are  certified  for  use 
without modification for an altitude of 10,100 feet (3,078 m). Consult 
the factory for installation at altitudes over 10,100 feet (3,078 m).
Some  gas  utility  companies  derate  their  gas  for  altitude,  making 
it unnecessary to install high altitude orifices. Call the local gas or 
utility company to verify BTU content.
Due to the input rate reduction at high altitudes, the output rating 
of the water heater is also reduced and should be compensated 
for in the sizing of the equipment for applications.
Some  circulating  pumps  are  manufactured  with  sealed 
bearings  and  do  not  require  further  lubrication.  Some 
circulating  pumps  must  be  periodically  oiled.  Refer  to 
the  pump  manufacturer’s  instructions  for  lubrication 
requirements.
CIRCULA
TING PUMP  WIRING DIAGRA M
STORAGE  TANK OR BUILDING RECIRCULA TION
FIELD SUPPLIED TEMPERATURE CONTROL
INST ALLED IN  THE STORAGE  TANK
OR CIRCULA TING LOOP RETURN LINE
CIRC
PUMP
MOT OR
L1 HOT
L2 NEUTRA L120 VA
C
POWER
CIRCULA TING PUMP  WIRING DIAGRA M
DISHW ASHER LOOP  WITH TOGGLE SWITC H
FIELD SUPPLIED  TEMPERATURE
CONTROL INST ALLED IN THE
CIRCUL ATING LOOP  RETURN LINE
DISHW
ASHER
T OGGLE
SWITCH
CIRC
PUMP
MOT OR
L1 HOT
L2 NEUTRA L120 VA
C
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 TO  ERRATIC CONTRO L SYSTEM 
OPERATION. 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 TO  ERRATIC CONTRO L SYSTEM 
OPERATION. 
CIRCULA TING PUMP  WIRING DIAGRA M
ST ORAGE  TANK OR BUILDING RECIRCULA TION
FIELD SUPPLIED TEMPERATURE CONTROL
INST ALLED IN  THE STORAGE  TANK
OR CIRCULA TING LOOP RETURN LINE
CIRC
PUMP
MOT OR
L1 HOT
L2 NEUTRA L120 VA
C
POWER
CIRCULA TING PUMP  WIRING DIAGRA M
DISHWASHER LOOP  WITH TOGGLE SWITC H
FIELD SUPPLIED  TEMPERATURE
CONTROL INST ALLED IN THE
CIRCUL ATING LOOP  RETURN LINE
DISHW
ASHER
T OGGLE
SWITCH
CIRC
PUMP
MOT OR
L1 HOT
L2 NEUTRA L120 VA
C
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 TO  ERRATIC CONTRO L SYSTEM 
OPERATION. 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 TO  ERRATIC CONTRO L SYSTEM 
OPERATION. 
FIGURE 9.  
						

							12
Some addition adjustment maybe required later to maintain 
a steady gas supply pressure.
5.  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
Water temperature over 125°F (52°C)
can cause severe burns instantly
resulting in severe injury or death.
Children, the elderly and the
physically or mentally disabled are at
highest risk for scald injury .
Feel water before bathing or
showering.
Te mperature limiting devices such as
mixing valves must be installed
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  the 
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 (°C) Time for 1st Degree Burn
 
(Less Severe Burns) Time for Permanent Burns
 
2nd & 3rd Degree  
(Most Severe Burns)
110 (43) (normal shower temp.)
116 (47) (pain threshold)
116 (47) 35 minutes 45 minutes
122 (50) 1 minute5 minutes
131 (55) 5 seconds 25 seconds
140 (60) 2 seconds 5 seconds
149 (65) 1 second2 seconds
154 (68) 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. 
(3.49  kPa)  (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. (0.37 kPa) from static to dynamic pressure to provide good 
performance. Pressure drops that exceed 1.5” W.C. (0.37 kPa) 
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. (3.49 kPa) (1/2 PSI Gauge). These systems must use 
field supplied regulators to lower the gas pressure to less than 
14”  W.C.  (3.49  kPa)  (1/2  PSI  Gauge).  Appliances  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 (34.5 kPa) 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.  (3.49  kPa)  (1/2  PSI 
Gauge) at any time must be equipped with a gas supply regulator.
GAS PRESSURE REQUIREMENTS
All models require a minimum gas supply pressure as shown in 
Table  3  on  page  8.  The  minimum  supply  pressure  is  measured 
while  gas  is  flowing  (dynamic  pressure).  The  supply  pressure 
(dynamic) should never fall below that indicated in Table 3 page 
8.  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.  (0.37  kPa) 
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 control valve on all models has a maximum gas supply 
pressure  limit  of  14"  W.C.  (3.48  kPa).  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.  Supply gas regulators shall have inlet and outlet connections 
not less than the minimum supply gas line size for the water 
heater they supply. See Table 7 on page 24.
3.  Positive  lock-up  gas  pressure  regulator(s)  should  be 
installed no closer than 3 feet (1 meter) and no farther than 8 
feet (2.4 meters) of equivalent length from the water heater’s 
inlet gas connection.
4.  After installing the positive lock-up gas pressure regulator(s) 
an initial nominal supply pressure setting of 7.0” W.C. (1.74 
kPa)  while  the  water  heater  is  operating  is  recommended 
and  will  generally  provide  good  water  heater  operation. 
INSTALLATION REQUIREMENTS  
						

							13
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  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.
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  agency  to  have  a 
thermal expansion tank installed.
See  Water  Line  Connections  on  page  21  and  Water  Piping 
Diagrams starting on page 35.
TEMPERATURE-PRESSURE RELIEF VALVE
Explosion Hazard
Temperature-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 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 
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. 
						

							14
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 
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 13.
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.
COMBUSTIBLE MATERIAL STORAGE
Fire or Explosion Hazar d
Read instruction manual befor e
installing, using or servicing water heater .
Avoid all ignition sources if you smell gas .
Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this or any other appliance.
Use only the gas shown on the water heater rating label.
Keep ignition sources away from faucets after extended
periods of non-use. Maintain required clearances to combustibles. Do not expose water heater controls to excessive gas
pressure.
Keep water heater area clear and free of combustible materials, 
gasoline and other flammable vapors and liquids.
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  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).  
						

							15
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.
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.
AIR REQUIREMENTS
Breathing Hazard - Carbon Monoxide Gas
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.
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   
						

							16
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  18  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 mm2 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 cm2). 
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  appliance.  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 mm2 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 (7.6 cm).   
						

							17
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  18  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.   
						

							18
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.
This heater is not approved for direct vent installation.
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 required 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 is exposed to ambient temperatures 
below 40°F (4.4°C) 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.
  FIGURE 11.  FIGURE 12.
• 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.
MULTIPLE HEATER MANIFOLD
Figure  13  and  tables  on  pages  19  and  20  should  be  used  for 
horizontally manifolding two or more heaters.
FIGURE 13.  
						

							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. 2006. 
TABLE 6. TECHNICAL DATA VENTING
Model BCL380T1206NOX
Input: 120,000 Btu/hrTotal Vent Height (Feet)
Vent connector size: 6 inches 6810 15203050100
Input Btu/hr Rise Vent Connector Diameter (Inches)
120,000 1 ft.66555555
120,000 2ft.55555555
120,000 3ft.55555555
Number of 120 Heaters Combined Input in 
Thousands of Btu/hr Manifold and Common Vent Diameter (Inches)
2 240,000 77666666
3 360,000 88777666
4 480,000 99988776
Model BCL380T1546NOX
Input: 154,000 Btu/hr Total Vent Height (Feet)
Vent connector size: 6 inches 6810 15203050100
Input Btu/hr Rise Vent Connector Diameter (Inches)
154,000 1 ft.66666666
154,000 2ft.66666666
154,000 3ft.66666666
Number of 154 Heaters Combined Input in 
Thousands of Btu/hr Manifold and Common Vent Diameter (Inches)
2 308,000 77666666
3 462,000 88777666
4 616,000 99988776
Model BCL380T1806NOX - 100T1996NOX
Input: 180,000 and 199,000 Btu/hr Total Vent Height (Feet)
Vent connector size: 6 inches 6810 15203050100
Input Btu/hr Rise Vent Connector Diameter (Inches)
180,000 1 ft.77666666
199,000 1 ft.77766666
180,000 2ft.66666666
199,000 2ft.77666666
180,000 3ft.66666666
199,000 3ft.66666666
Number of Heaters Combined Input in 
Thousands of Btu/hr Manifold and Common Vent Diameter (Inches)
2 360,000
88877766
398,000 88877766
3 540,000
109998877
597,000 109998877
4 720,000
12121010 9988
796,000 12121010 9988
Model BCL3100T2506NOX
Input: 250,000 Btu/hr Total Vent Height (Feet)
Vent connector size: 6 inches 6810 15203050100
Input Btu/hr Rise Vent Connector Diameter (Inches)
250,000 1 ft.88777666
250,000 2ft.77776666
250,000 3ft.77776666
Number of 250 Heaters Combined Input in 
Thousands of Btu/hr Manifold and Common Vent Diameter (Inches)
2 500,000 99988777
3 750,000 1212101010 988
4 1,000,000 141412121010 99  
						

							20
TABLE 6. TECHNICAL DATA VENTING (Continued)
Model BCL3100T2756NOX
Input: 275,000 btu/hrTotal Vent Height (Feet)
Vent connector size: 6 inches 6810 15203050100
Input Btu/hr Rise Vent Connector Diameter (Inches)
275,000 1 ft.88877666
275,000 2 ft.88777666
275,000 3 ft.77777666
Number of Heaters Combined Input (Btu/hr) Manifold and Common Vent Diameter (Inches)
2 550,0001010 998877
3 825,0001412121010 998
4 1,100,00014141412121210 9
Model BCL386T3106NOX
Input: 310,000 btu/hr Total Vent Height (Feet)
Vent connector size: 6 inches 6810 15203050100
Input Btu/hr Rise Vent Connector Diameter (Inches)
310,000 1 ft.-8 887766
310,000 2 ft.88877766
310,000 3 ft.88877766
Number of Heaters Combined Input (Btu/hr)
2 620,000121010 99887
3 930,000141412121010 99
4 1,240,00016141414121210 9
Model BCL386T3666NOX
Input: 366,000 btu/hr Total Vent Height (Feet)
Vent connector size: 6 inches 6810 15203050100
Input Btu/hr Rise Vent Connector Diameter (Inches)
366,000 1 ft.---8 8776
366,000 2 ft.--8 88776
366,000 3 ft.-8 887766
Number of Heaters Combined Input (Btu/hr)
2 732,00012121210 9988
3 1,098,00014141412121210 9
4 1,464,0001616161414121210
Model BCL386T3996NOX
Input: 390,000 btu/hr Total Vent Height (Feet)
Vent connector size: 6 inches 6810 15203050100
Input Btu/hr Rise Vent Connector Diameter (Inches)
390,000 1 ft.----8 776
390,000 2 ft.---8 8776
390,000 3 ft.--8 88776
Number of Heaters Combined Input (Btu/hr)
2 780,0001212121010 998
3 1,170,00016141414121210 9
4 1,560,0001616161414141210