A.O. Smith 104 Series User manual

COMMERCIAL GAS WATER HEATERS
Instruction Manual
PRINTED 0814 194186-003
PLACE THESE INSTRUCTIONS ADJACENT TO HEATER AND NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.
MODELS BTP 139(A) Thru 370(A)
SERIES 104/105
INSTALLATION - OPERATION - SERVICE
- MAINTENANCE - LIMITED WARRANTY
Read and understand this instruction
manual and the safety messages
herein before installing, operating or
servicing this water heater.
Failure to follow these instructions and
safety messages could result in death
or serious injury.
This manual must remain with the
water heater.
500 Tennessee Waltz Parkway
Ashland City, TN 37015
Low Lead Content
Thank yRX IRr EXyinJthis enerJy eI¿Fient water heater
We aSSreFiate yRXr FRn¿denFe in RXr SrRdXFts
WARNING: If the information in these
instructions is not followed exactly, a fire
or explosion may result causing property
damage, personal injury or death.
Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS:
Do not try to light any appliance.
Do not touch any electrical switch; do
not use any phone in your building.
Immediately call your gas supplier
from a neighbor’s phone. Follow the
gas supplier’s instructions.
If you cannot reach your gas supplier,
call the fire department.
Installation and service must be
performed by a qualified installer,
service agency or the gas supplier.





2
Air )rRP 2ther IndRRr 6SaFes 18
9ent CRnneFtiRn 19
WATER HEATER INSTALLATION 19-22
Water Line CRnneFtiRns 19
TP 9alYe DisFharJe PiSe 19
Installation Diagrams - Top Inlet/Outlet Usage 20
Burner Installation 20
Heater Wiring  21
Gas Piping 22
Gas Line Leak Testing  22
Purging  22
STARTUP AND OPERATION  23
Prior to Start Up  23
SEQUENCE OF OPERATION 23-27
SeTuenFe oIOperation Flow Chart  24
Lighting & Operation Label  25
Adjustments 26
CheFking 9enting  26
CheFking the Input  26
Setting Burner Operation27
MAINTENANCE28-32
9enting System and BarometriFDraIt Control  28
General 28
Remote Storage Tank Temperature Control 28
Temperature-Pressure Relief Valve Test 28
Anode Rod InspeFtion 29
Draining and Flushing  29
ReFommended ProFedure for PeriodiFRemoval or Lime Deposits
from the Tank Type CommerFial Water Heaters  29
DeLiming Solvents  30
Tank Cleanout ProFedure  30
Deliming Using Flo-Jug Method 30-31
Power Burner  31-32
Gas Control Valve  32
SERVICE  32
EleFtriFal ServiFing  32
TROUBLESHOOTING CHECKLIST  33
FOR YOUR INFORMATION 34
Start up Conditions  34
Operational Conditions  34
WATER PIPING DIAGRAMS35-49
MANIFOLD KITS  50
REPLACEMENT PARTS LIST  51-52
NOTES 53-54
WARRANTY  55
TABLE OF CONTENTS
SAFE INSTALLATION, USE AND SERVICE 3
APPROVALS 3
GENERAL SAFETY INFORMATION4-5
PreFautions  5
Grounding InstruFtions 5
Hydrogen Gas Flammable 5
INTRODUCTION  6
Abbreviations Used 6
Quali¿Fations  6
Start Up Requirements  6
Preparing for the Installation 6
FEATURES AND COMPONENTS  7
High Limit SwitFh 7
EleFtroniFIgnition Control 7
BarometriFDraft Control  7
Combustion Chamber Observation Port  7
UnFrating 7
INSTALLATION CONSIDERATIONS 8-12
Rough In Dimensions 8
LoFating The Water Heater 10
ClearanFes  10
Insulation Blanket11
Hard Water 11
CirFulation Pumps 11-12
High Altitude Installations  12
INSTALLATION REQUIREMENTS  13-16
Gas Supply Systems 13
Supply Gas Regulator 13
Power Supply  13
Water Temperature Control and Mixing Valves  13
Dishwashing MaFhines  14
Closed Water Systems 14
Thermal Expansion 14
Temperature-Pressure Relief Valve 14-15
Contaminated Air  15
Air Requirements  15
UnFon¿ned SpaFe 16
Con¿ned SpaFe 16
VENTING INSTALLATION  16-19
Venting  16
BarometriFDraft Control Assembly  16
Fresh Air Opening for Con¿ned SpaFes 17
Outdoor Air Through Two Openings  17
Outdoor Air Through One Opening  17
Outdoor Air Through Two Horizontal DuFts 17
Outdoor Air Through Two VertiFal DuFts 18

3
SAFE INSTALLATION, USE AND SERVICE
The proper installation, use and serviFing of this water heater is extremely important to your safety and the safety of others
Many safety-related messages and instruFtions have been provided in this manual and on your own water heater to warn you and
others of a potential injury hazardRead and obey all safety messages and instruFtions throughout this manualIt is very important
that the meaning of eaFh safety message is understood by you and others who install, use, or serviFe this water heater
All safety messages will generally tell you about the type of hazard, what Fan happen if you do not follow the safety message, and
how to avoid the risk of injury
The California Safe Drinking Water and ToxiFEnforFement AFt requires the Governor of California to publish a list of substanFes
known to the State of California to Fause FanFer, birth defeFts, or other reproduFtive harm, and requires businesses to warn of
potential exposure to suFh substanFes
WARNING: This produFt Fontains a FhemiFal known to the State of California to Fause FanFer, birth defeFts, or other reproduFtive
harmThis applianFe Fan Fause low level exposure to some of the substanFes listed in the AFt
DANGER
WARNING
CAUTION
CAUTION
DANGER indicates an imminently
hazardous situation which, if not avoided,
will result in injury or death.
This is the safety alert symbol. It is used to alert you to
potential personal injury hazards. Obey all safety
messages that follow this symbol to avoid possible
injury or death.
WARNING indicates a potentially hazardous
situation which, if not avoided, could result
in injury or death.
CAUTION indicates a potentially hazardous
situation which, if not avoided, could result in
minor or moderate injury.
CAUTION used without the safety alert
symbol indicates a potentially hazardous
situation which, if not avoided, could result in
property damage.
APPROVALS
Note: ASME FonstruFtion is optional on the water heaters Fovered in this manual
Low Lead Content

4
GENERAL SAFETY INFORMATION
Fire or Explosion Hazard
Read instruction manual before
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.
Property Damage Hazard
All water heaters eventually leak.

Do not install without adequate drainage.

CAUTION
Fire and Explosion Hazard
Leak test before placing the
water heater in operation.
Disconnect gas piping and main
gas shutoff valve before leak
testing.
Install sediment trap in
accordance with NFPA 54.
Use joint compound or Teflon tape
compatible with propane gas.
Turn off power to the water heater
before performing any service.
Electrical Shock Hazard

Label all wires prior to disconnecting
when performing service. Wiring errors
can cause improper and dangerous
operation.

Verify proper operation after servicing.

Failure to follow these instructions can
result in personal injury or death.

Fire Hazard
For continued protection against
risk of fire:

Do not install water heater on
carpeted floor.

Do not operate water heater if
any part has been exposed to
flooding or water damage.
Fire and Explosion Hazard
Turn off gas lines during installation.
Contact a qualified installer or service
technician for installation and service.
Excessive gas pressure to gas valve can
cause serious injury or death.
Do not use water heater with any gas
other than the gas shown on the rating
label.
Jumping out control circuits or components can
result in property damage, personal injury or death.
Service should only be performed by a qualified service
technician using proper test equipment.

Altering the water heater controls and/or wiring in any way
could result in permanent damage to the controls or water
heater and is not covered under the limited warranty.

Any bypass or alteration of the water
heater controls and/or wiring will result
in voiding the water heater warranty.
Altering the water heater controls and/or wiring in any way
could result in altering the ignition sequence allowing gas to
flow to the main burner before the hot surface igniter is at
ignition temperature causing delayed ignition which can
cause a fire or explosion.


5
PRECAUTIONS
DO NOT USE THIS WATER HEATER IF ANY PART HAS
BEEN E;POSED TO FLOODING OR WATER DAMAGE
Immediately Fall a qualified serviFe teFhniFian to inspeFt the
water heater and to make a determination on what steps
should be taken next
If the unit is exposed to the following, do not operate heater
until all ForreFtive steps have been made by a qualified
serviFe teFhniFian
1External ¿re
2Damage
3Firing without water
GROUNDING INSTRUCTIONS
This water heater must be grounded in aFFordanFe with the
National EleFtriFal Code and/or loFal FodesThese must be
followed in all Fases
This water heater must be FonneFted to a grounded, permanent
wiring systemor an equipment grounding FonduFtor must be
run with the FirFuit FonduFtors and FonneFted to the equipment
grounding terminal or lead on the water heater, see Figure 19
HYDROGEN GAS FLAMMABLE
Explosion Hazard
Flammable hydrogen gases
may be present.
Keep all ignition sources away
from faucet when turning on
hot water.
Hydrogen gas Fan be produFed in a hot water system served
by this water heater that has not been used for a long period of
time generally two weeks or more Hydrogen gas is extremely
ÀammableTo red uFe the risk of injury under these Fonditions,
it is reFommended that a hot water fauFet served by this water
heater be opened for several minutes before using any eleFtriFal
applianFe FonneFted to the hot water systemIf hydrogen is
present there will probably be an unusual sound suFh as air
esFaping through the pipe as the water begins to ÀowTHERE
SHOULD BE NO SMOKING OR OPEN FLAME NEAR THE
FAUCET AT THE TIME IT IS OPEN
GENERAL SAFETY INFORMATION
Verify the power to the water heater is turned off before performing any service procedures.
Read and understand this instruction
manual and the safety messages
herein before installing, operating or
servicing this water heater.
Failure to follow these instructions and
safety messages could result in death
or serious injury.
This manual must remain with the
water heater.
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.
Temperature limiting devices such as
mixing valves must be installed
when required by codes and to
ensure safe temperatures at fixtures.
Explosion Hazard
Overheated water can cause
water tank explosion.
Properly sized temperature and
pressure relief valve must be
installed in the opening provided.
GENERAL SAFETY INFORMATION
Improper installation, use and service may result
in property damage.
 Do not operate water heater if any part has been exposed
to flooding or water damage.
 Inspect anode rods regularly, replace if damaged.
 Install in location with drainage.
 Fill tank with water before operation.
 Properly sized thermal expansion tanks are required on all
closed water systems.
Refer to this manual for installation and service.
CAUTION

6
INTRODUCTION
Thank You for purFhasing this water heaterProperly installed
and maintained, it should give you years of trouble free serviFe
ABBREVIATIONS USED
Abbreviations found in this InstruFtion Manual inFlude 
ANSI - AmeriFan National Standards Institute
ASME - AmeriFan SoFiety of MeFhaniFal Engineers
AHRI - Air-Conditioning, Heating and Refrigeration Institute
NEC - National EleFtriFal Code
NFPA - National Fire ProteFtion AssoFiation
UL - Underwriters Laboratory
CSA - Canadian Standards AssoFiation
QUALIFICATIONS
QUALIFIED INSTALLER OR SERVICE AGENCY
Installation and serviFe of this water heater requires ability
equivalent to that of a Quali¿ed AgenFy as de¿ned by ANSI
belowin the ¿eld involvedInstallation skills suFh as plumbing,
air supply, venting, gas supply and eleFtriFal supply are required
in addition to eleFtriFal testing skills when performing serviFe
ANSI Z223.1 2006 Sec. 3.3.83: ³Quali¿ed AgenFy´- ³Any
individual, ¿rm, Forporation or Fompany that either in person or
through a representative is engaged in and is responsible for (a)
the installation, testing or replaFement of gas piping or (b) the
FonneFtion, installation, testing, repair or serviFing of applianFes
and equipmentthat is experienFed in suFh workthat is familiar
with all preFautions requiredand that has Fomplied with all the
requirements of the authority having jurisdiFtion´
If you are not quali¿ed (as de¿ned by ANSI above) and liFensed
or Ferti¿ed as required by the authority having jurisdiFtion
to perform a given task do not attempt to perform any of the
proFedures desFribed in this manualIf you do not understand
the instruFtions given in this manual do not attempt to perform
any proFedures outlined in this manual
START UP REQUIREMENTS
This produFt requires a formal Start-Up by an authorized
serviFe/
start-up provider that has been approved by the manufaFturer
for this speFi¿F produFtCall 1-800-527-1953 to loFate the
nearest authorized start-up provider and arrange a faFtory
start-upPlease provide as muFh notiFe as possible, preferably
2 weeksPlease have the model and serial number ready when
you Fall
This start-up is required to aFtivate the warranty and ensure
safe, ef¿Fient operation
Warranty on this produFt is limited and Fould be void in the
event the unit is not installed per the instruFtions in this manual
and/or not started up by an authorized faFtory trained serviFe/
start-up provider
PREPARING FOR THE INSTALLATION
1Read the ³General Safety´seFtion, page 4-5 of this manual
first and then the entire manual FarefullyIf you don¶t follow
the safety rules, the water heater will not operate properly
It Fould Fause DEATH, SERIOUS BODILY INJURY AND/OR
PROPERTY DAMAGE
This manual Fontains instruFtions for the installation, operation,
and maintenanFe of the gas-¿red water heaterIt also Fontains
warnings throughout the manual that you must read and be
aware ofAll warnings and all instruFtions are essential to the
proper operation of the water heater and your safetySinFe we
Fannot put everything on the ¿rst few pages, READ THE ENTIRE
MANUAL BEFORE ATTEMPTING TO INSTALL OR OPERATE
THE WATER HEATER
2The installation must Fonform with these instruFtions and the
loFal Fode authority having jurisdiFtionIn the absenFe of loFal
Fodes, the installation must Fomply with the Furrent editions
of the National Fuel Gas Code, ANSI =2231/NFPA 54 or CAN/
CSA-B1491 the Natural Gas and Propane Installation Code
All doFuments are available from the Canadian Standards
AssoFiation, 8501 East Pleasant Valley Road, Cleveland, OH
44131NFPA doFuments are also available from the National
Fire ProteFtion AssoFiation, 1 BatterymarFh Park, QuinFy, MA
02269
3If after reading this manual you have any questions or do
not understand any portion of the instruFtions, Fall the loFal
gas utility or the manufaFturer whose name appears on the
rating plate
4Carefully plan the plaFe where you are going to put the
water heaterCorreFt Fombustion, vent aFtion, and vent pipe
installation are very important in preventing death from possible
Farbon monoxide poisoning and ¿res
Examine the loFation to ensure the water heater Fomplies with
the ³LoFating the New Water Heater´seFtion in this manual
5For California installation this water heater must be braFed,
anFhored, or strapped to avoid falling or moving during
an earthquakeSee instruFtions for ForreFt installation
proFeduresInstruFtions may be obtained from California
OffiFe of the State ArFhiteFt, 400 P Street, SaFramento,
CA 95814
6MassaFhusetts Code requires this water heater to be installed in
aFFordanFe with MassaFhusetts 248-CMR 200State Plumbing
Code and 248-CMR 500

7
HIGH LIMIT SWITCH
The dual bulb Fontroller (¿g1) Fontains the high limit (energy Futoff)
sensorThe high limit switFh interrupts main burner gas Àow should
the water temperature reaFh 205F (96C)
In the event of high limit switFh operation, the applianFe Fannot be
restarted unless the water temperature is reduFed by at least 20F
(11C) and the high limit reset button on front of limit Fontrol (¿g1)
is depressed
Continued manual resetting of high limit Fontrol, preFeded by higher
than usual water temperature is evidenFe of high limit switFh operation
The following is a possible reason for high limit switFh operation
A malfunFtion in the thermostatiFFontrols would allow the gas
Fontrol valve to remain open Fausing water temperature to
exFeed the thermostat settingThe water temperature would
Fontinue to rise until high limit switFh operation
ContaFt your dealer or serviFe agent if Fontinued high limit switFh
operation oFFurs
DIGITAL THERMOSTAT
FIGURE 1.
ELECTRONIC IGNITION CONTROL
EaFh heater is equipped with a Honeywell ignition moduleThe
DireFt Spark Ignition Control Module Fontrols the ignition
sequenFe and gas Fontrol operation of the water heater
IGNITION MODULE
FIGURE 2.
BAROMETRIC DRAFT CONTROL
The heater is equipped with a double aFting barometriFdraft
FontrolThis Fontrol assembly is faFtory adjusted to automatiFally
regulate the Fhimney draft imposed on the unit
BAROMETRIC DRAFT CONTROL
FIGURE 3.
COMBUSTION CHAMBER OBSERVATION PORT
The Fombustion Fhamber observation aFFess panel is loFated
above and to the left of the burnerA plug loFated under the
panel, see fig5, is inserted into the Fombustion Fhamber wall
This plug should not be removed exFept, in rare Fases, when
the Fombustion Fhamber requires Fleaning or replaFement
FIGURE 4.
UNCRATING
UnFrate the heater by removing the outside mat and top loFator
The shipping pallet must be removed from the unitIt may be
possible to simply unbolt the base from the pallet and, with
the help of 2 or more persons, work the unit off the pallet
Some units will be too heavy and will require the use of jaFks
or lifting equipment to safely remove the pallet and move the
unit into positionBe Fareful when moving this heaterIt will
tip over easily
The heater is shipped with a burner and draft FontrolThe
burner and draft Fontrol are shipped in separate FartonsThey
should be installed as reFeived without any alterations
DisFard the shipping Frate and paFkaging Fartons in an
appropriate manner
FEATURES AND COMPONENTS

8
ROUGH IN DIMENSIONS
INSTALLATION CONSIDERATIONS
FIGURE 5.
TABLE 1 . MODELS BTP-139(A) THROUGH BTP-370(A)
MODELS A B C DE G H JGAS
APPROX. SHIP. WT.
(LBS.) IN OUT
ASME STD.
BTP-139/A 74 3/4"
65 " 26 3/4 " 6" 21 3/8" 27 3/4 " 38" 85 1/4" 1/2 658 556 1 1/2" 1 1/2"
BTP-199/A 74 3/4"
65 " 26 3/4 " 6" 21 3/8" 27 3/4 " 38" 85 1/4" 1/2 635 545 1 1/2" 1 1/2"
BTP-270/A 74 3/4" 65 " 26 3/4 " 8" 21 3/8" 27 3/4 " 38" 85 1/4" 3/4 632 547 1 1/2" 1 1/2"
BTP-370/A 74 3/4" 65 " 26 3/4 " 8" 21 3/8" 27 3/4 " 38" 85 1/4" 3/4 731 634 1 1/2" 1 1/2"

9
TABLE 2. HEATER PERFORMANCE DATA BTP MODELS
MODELS
STORAGE
CAPACITY
U.S. GALLONS
IMPUT RATING BTU/HR. RECOVERY RATE
GPH@100°F RISE
RECOVERY RATE
GPH@140°F RISE
MAXIMUM
AMPERES
120V, 60Hz, 10
BTP-139/A 81 140,000 136 97 5
BTP-199/A 81 199,000 193 138 5
BTP-270/A 81 270,000 262 187 5
BTP-370/A 81 370,000 359 256 5
Models with letter ³A´following the model number have the optional ASME tank FonstruFtion
The BTP-370 is available in natural gas only
TABLE 3. GAS AND ELECTRICAL CHARACTERISTICS
Model Type of Gas
Gas Supply Pressure
Gas Manifold Pressure Volts/Hz AmperesMinimum Maximum
All Models Natural 45" WC(112 kPa) 14" WC(348 kPa) 35" WC(087 kPa) 120/60 <5
All Models * Propane 45" WC(112 kPa) 14" WC(348kPa) 35" WC(087 kPa) 120/60 <5
* Model BTP-370(A) is not available in Propane
INSTALLATION CONSIDERATIONS

10
The heater must not be loFated in an area where it will be
subjeFt to freezing
LoFate it near a Àoor drainThe heater should be loFated
in an area where leakage from heater or FonneFtions will
not result in damage to adjaFent area or to lower Àoors of
the struFture
When suFh loFations Fannot be avoided, a suitable metal
drain pan should be installed under heaterSuFh pans
should be fabriFated with sides at least 2´deep, with length
and width at least 2´greater than diameter of heater and
must be piped to an adequate drainPan must not restriFt
Fombustion air Àow
CLEARANCES
These heaters are approved for installation on non-Fombustible
flooring in an alFove when the minimum FlearanFe from
Fombustion or non-Fombustible FonstruFtion are followed as
indiFated in Figure 7 and Table 5
Units whiFh are to be installed on Fombustible Àooring must
be supported by a full layer of hollow FonFrete bloFks, from
8" to 12"
thiFk and extending 12" (minimum) beyond the heater in all
direFtionsThe FonFrete bloFks must provide an unbroken
FonFrete surfaFe under the heater with the hollows running
Fontinuously and horizontallyA 3/16 inFh steel plate must
Fover the FonFrete bloFksSee Figure 5
PROPER INSTALLATION ON COMBUSTIBLE FLOORING
FIGURE 6.
In all installations the minimum Fombustible FlearanFes from
barometriFdraft Fontrol surfaFe or vent piping shall be 6´
(152mm)Vent piping passing through a Fombustible wall or
Feiling must be a Fontinuous run (no joints) and retain 6´
(152mm) FlearanFe unless an approved reduFing thimble is used
A serviFe FlearanFe of 24´(610mm) should be maintained from
serviFeable parts, suFh as relief valves, bafÀes, thermostats,
Fleanout openings or drain valves
TABLE 5. INSTALLATION CLEARANCES
A
(RIGHT SIDE)
B
(LEFTSIDE)
C
(BACK)
D
(CEILING)
BTP-139(A) 6" (1524 Fm) 6" (1524 Fm) 6" (1524 Fm) 21" (5334 Fm)
BTP-199(A) 6" (1524 Fm) 6" (1524 Fm) 6" (1524 Fm) 21" (5334 Fm)
BTP-270(A) 6" (1524 Fm) 6" (1524 Fm) 6" (1524 Fm) 21" (5334 Fm)
BTP-370(A) 6" (1524 Fm) 6" (1524 Fm) 6" (1524 Fm) 24" (6096 Fm)
LOCATING THE WATER HEATER
Property Damage Hazard
All water heaters eventually leak.

Do not install without adequate drainage.

CAUTION
When installing the heater, Fonsideration must be given to
proper loFationLoFation seleFted should be as Flose to the
staFk or Fhimney as praFtiFable, with adequate air supply and
as Fentralized with the piping system as possible
Fire or Explosion Hazard
Read instruction manual before
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.
There is a risk in using fuel burning applianFes suFh as gas water
heaters in rooms, garages or other areas where gasoline, other
Àammable liquids or engine driven equipment or vehiFles are stored,
operated or repairedFlammable vapors are heavy and travel
along the Àoor and may be ignited by the heater¶s igniter or main
burner Àames Fausing ¿re or explosionSome loFal Fodes permit
operation of gas applianFes in suFh areas if they are installed 18´
or more above the ÀoorThis may reduFe the risk if loFation in
suFh an area Fannot be avoided
Do not install this water heater direFtly on a Farpeted ÀoorA ¿re
hazard may resultInstead the water heater must be plaFed on a
metal or wood panel extending beyond the full width and depth by at
least 3 inFhes in any direFtionIf the heater is installed in a Farpeted
alFove, the entire Àoor shall be Fovered by the panelAlso, see the
DRAINING requirements in MAINTENANCE SeFtion
The heater shall be loFated or proteFted so it is not subjeFt to physiFal
damage by a moving vehiFle
Flammable items, pressurized Fontainers or any other potential
¿re hazardous artiFles must never be plaFed on or adjaFent to
the heaterOpen Fontainers or Àammable material should not be
stored or used in the same room with the heater
INSTALLATION CONSIDERATIONS