A.O. Smith PREFERRED BPD 400 Installation and user guide

1
A DIVISION OF A.O. SMITH CORPORATION
Mc BEE, SOUTH CAROLINA
PLACE THESE INSTRUCTIONS ADJACENT TO HEATERAND
NOTIFYOWNER TOKEEP FORFUTURE REFERENCE.
PRINTED IN U.S.A. 0206 Part Number 197279-000
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.
• Ifyoucannotreach yourgas supplier,
call the fire department.
– Installation and service must be
performed by a qualified installer,
service agency or the gas supplier.
AOS PREFERRED-BPD400 DIRECT VENT
COMMERCIALGAS WATER HEATER
GAS-FIREDINDUCEDDRAFT
FOR DOMESTIC HOT WATER
Thank you for buying this energy efficient water heater from
A.O. Smith Water Products Company. We appreciate your
confidenceinourproducts.
CAUTION
TEXT PRINTED OR OUTLINED IN RED CONTAINS
INFORMATION RELATIVE TO YOUR SAFETY. PLEASE
READ THOROUGHLYBEFORE INSTALLING AND USING
THISAPPLIANCE.
•INSTALLATION • OPERATION • SERVICE • MAINTENANCE •LIMITEDWARRANTY

2
Input Capacity SHIPPING
BTU Gallon GAS WEIGHT
Model (kw-Hr.) (Liters) "A" "B" "C" "D" "E" "F" "G" "H" "I" LINE STD ASME
BPD - 400 390,000 95 82.25 80.25 30.25 8.75 4 or 6 21.75 63.50 2.25 58.00 1.00 900lbs. 1100lbs.
(114.3) (360) (209) (204) (77) (22) vent (55) (161) (8) (147) (2.54) 408Kg 499Kg
DIMENSIONS IN INCHES (CM)
FRONT
TOP
Table 1. RECOVERYCAPACITIES-NATURALGAS
Input Capacity TEMPERATURE RISE - DEGREESF-GALLONS PER HOUR (LPH)
BTU Gallon 30 F 40 F 50 F 60 F 70 F 80 F 90 F 100 F 110 F 120 F 130 F 140 F
Model (kw-Hr.) (Liters) 17 C 22 C 28 C 33 C 39 C 44 C 50 C 56 C 61 C 67 C 72 C 78 C
BPD - 400 390,000 95 1316 987 789 658 564 493 439 395 359 329 304 282
(114.3) (360) (4981) (3735) (2988) (2490) (2135) (1868) (1660) (1494) (1358) (1245) (1149) (1067)
Recovery capacities are based on heater performance at 83.5% thermal efficiency.
GAS VALVE PIPING
BPD-400 3/4" NPT
ROUGH-INDIMENSIONS

3
TYPICAL INSTALLATION
INTAKE FOR
COMBUSTION AIR
VENT TO
OUTDOORS
FLUE PRODUCTS
DISCHARGE PIPE
AIRINTAKE PIPE
TEMPERATURE
PRESSURE RELIEF
VALVE
VACUUMRELIEFREQUIREDBYSOME
CODES(REFERTO LOCAL CODES)
SHUTOFFVALVE
COLD WATER INLET
MIXING VALVE*
TEMPERED
WATER OUTLET
HOTWATEROUTLET
GAS
SUPPLY
Installation Information: for Model BPD 400 100 Series
ELECTRICAL CLEARANCES PRESSURES ORIFICES INPUT
120/24VAC 60Hz 5A FRONT SIDES TOP NATURAL NATURAL NATURAL 390kbtuh
UNIT IS POLARITY SENSITIVE 6"=(15cm) 0" 12"=(30.5cm) Manifold 4.50" WC Sea Level 0.126
Inlet 7.00" WC 4500' 0.126
Max.Inlet 14.00" WC 8000' 0.106

4
These designs comply with the current version of the American National
Standard for Gas Water Heaters, Volume III, ANSI Z21.10.3 / CSA 4.3 as
automatic circulating tank water heaters, and automatic storage water
heaters.
Detailed installation diagrams are found in this manual. These diagrams will
serve to provide the installer with a reference for the materials and methods
of piping necessary. It is highly essential that all water, gas piping and
wiring be installed as shown on the diagrams.
Particular attention should be given to the installation of thermometers at
the locations indicated on the diagrams as these are necessary for checking
the proper functioning of the heater.
In addition to these instructions, the equipment shall be installed in
accordance with those installation regulations in force in the local area
where the installation is to be made. These shall be carefully followed in all
cases. Authorities having jurisdiction should be consulted before
installations are made.
In the absence of local codes, the installation must comply with the current
editions of the National Fuel Gas Code, ANSI Z223.1/NFPA 54 and the
NationalElectricCode.Theformer is available from the Canadian Standards
Association, 8501 East Pleasant Valley Road, Cleveland, OH 44131, and
both documents are available from the National Fire ProtectionAssociation,
1 Batterymarch Park, Quincy, MA 02269.
FOREWORD
TABLE OF CONTENTS
ROUGH-INDIMENSIONS ................................................................... 2
TYPICALINSTALLATION .................................................................. 3
FOREWARD ...................................................................................... 4
GENERALSAFETYINFORMATION .................................................. 5
Precautions .................................................................................. 5
Chemical Vapor Corrosion ........................................................... 5
ImproperCombustion ................................................................... 5
Extended Nonuse Periods ........................................................... 5
Insulation Blankets ....................................................................... 5
High Altitude Installations ............................................................. 5
FEATURES ........................................................................................ 6
TheEliminator ............................................................................... 6
High Limit Switch (E.C.O.) ............................................................ 6
CirculatingPump........................................................................... 6
Dishwashing Machine Requirement ............................................ 6
Electronic Ignition Control ............................................................. 7
PilotAssembly .............................................................................. 7
Gas Valve..................................................................................... 7
Pressure Switch .......................................................................... 7
Step Down Transformer .............................................................. 8
Burner Tray Assembly ................................................................. 8
Burner Tray .................................................................................. 8
Burner .......................................................................................... 8
Burner Orifice .............................................................................. 8
Blower Assembly......................................................................... 8
High Limit Switch .......................................................................... 9
Shroud Assembly......................................................................... 9
Temperature and Pressure Release Valve ................................. 9
INSTALLATIONINSTRUCTIONS ........................................................ 9
Required Ability ............................................................................ 9
Hard Water ................................................................................... 9
Locating the Heater...................................................................... 9
Leveling ........................................................................................ 9
Clearances ................................................................................... 10
Alcove Installation ........................................................................ 10
Air Requirements ......................................................................... 10
COMBUSTIONAIRANDEXHAUST ................................................... 10
Venting Clearances...................................................................... 10
Facts to Consider About the Location ......................................... 11
Wire Fence ................................................................................... 11
WaterPiping ................................................................................. 12
Temperature-Pressure Relief Valve ............................................ 12
PAGE PAGE
Filling the Water Heater................................................................ 13
Wiring ........................................................................................... 13
Venting ......................................................................................... 15
Venting Through Roof .................................................................. 19
GASPIPING ....................................................................................... 20
SedimentTrap .............................................................................. 20
INSTALLATIONCHECKLIST .............................................................. 21
Operating Instructions for Model 100-400 .................................. 22
Operational Sequence (Natural Gas Models Only) ..................... 22
Safety Sequence (Natural Gas Models Only)............................. 22
Robertshaw Control System (Natural Gas) ................................ 22
FORYOURSAFETY......................................................................... 23
Operating Instructions ................................................................. 23
To Turn Off Gas to Appliance ...................................................... 23
TemperatureRegulation ............................................................... 24
Temperature Adjustments ............................................................ 24
STARTUPCONDITIONS .................................................................... 24
Condensation ............................................................................... 24
Smoke/Odor.................................................................................. 25
ThermalExpansion....................................................................... 25
Strange Sounds ........................................................................... 25
OPERATIONALCONDITIONS ............................................................ 25
Smelly Water ................................................................................ 25
Air in Hot Water Faucets ............................................................. 25
Venting Manual Reset Switch...................................................... 25
High Temperature Shut Off System ............................................. 25
E.C.O. ........................................................................................... 25
Not Enough or No Hot Water........................................................ 25
Water Is Too Hot........................................................................... 26
Venting System Inspection .......................................................... 26
Burner Inspection......................................................................... 26
Burner Cleaning ........................................................................... 26
Housekeeping .............................................................................. 27
Draining ........................................................................................ 27
Service ......................................................................................... 27
INSTALLATIONDIAGRAMS .............................................................. 28
Manifold Kits................................................................................. 33
SedimentRemoval........................................................................ 34
LimeScaleRemoval ..................................................................... 34
Anode Inspection and Replacement............................................ 34
Replacement Parts ....................................................................... 34
MODELBPD400LIMITEDWARRANTY............................................ 35

5
SERVED BYTHIS HEATER THATHAS NOTBEEN USED FORALONG
PERIOD OF TIME (GENERALLY TWO WEEKS OR MORE). HYDROGEN
GAS IS EXTREMELY FLAMMABLE. To reduce the risk of injury under
these conditions, it is recommended that the hot water faucet be opened
for several minutes at the kitchen sink before using any electrical appliance
connected to the hot water system. If hydrogen is present, there will
probably be an unusual sound such as air escaping through the pipe as
the water begins to flow. THERE SHOULD BE NO SMOKING OR OPEN
FLAMENEARTHEFAUCETATTHETIMEITIS OPEN.
INSULATION BLANKETS
Insulation blankets available to the general public for external use on
gas water heaters are not approved for use on your A.O. Smith water
heater. The purpose of an insulation blanket is to reduce the standby
heat loss encountered with storage tank water heaters. Your A.O.Smith
water heater meets or exceeds theASHRAE/IES 90.1b-1999standards
with respect to insulation and standby loss requirement making an
insulation blanket unnecessary.
DANGER
Should you choose to apply an insulation blanket to this heater,
you should follow these instructions. Failure to follow these
instructions can result 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 venting components.
•Do not cover the gas valve or temperature & pressure relief valve.
•Do not cover the instruction manual. Keep it on the side of the
water heater or nearby for future reference.
•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" (23 cm) of floor, (within 2"
(5cm) of bottom cover) to prevent blockage of combustion air flow
to the burners.
•Do inspect the insulation blanket frequently to make sure it does not
sag, thereby obstructing combustion air flow.
•Do obtain new labels from A.O. Smith for placement on the blanket
directly over the existing labels.
HIGH ALTITUDE INSTALLATIONS
DANGER
INSTALLATIONS ABOVE 2000 FEET (610 METERS) REQUIRE
REPLACEMENT OF THE BURNER ORIFICES IN ACCORDANCE WITH
SECTION 8.1.2 OF THE NATIONAL FUEL GAS CODE (ANSI Z223.1).
FAILURETOREPLACETHE ORIFICES WILLRESULTIN IMPROPERAND
INEFFICIENT OPERATION OF THE APPLIANCE RESULTING IN THE
PRODUCTIONOFINCREASEDLEVELSOF CARBON MONOXIDEGASIN
EXCESSOFSAFELIMITSWHICHCOULDRESULTINSERIOUSPERSONAL
INJURYORDEATH.
You should contact your gas supplier for any specific changes which
may be required in your area.
As elevation above sea level is increased, there is less oxygen per cubic
GENERAL SAFETY INFORMATION
PRECAUTIONS
DONOTUSETHISAPPLIANCEIFANYPARTHAS BEEN UNDER WATER.
Immediately call a qualified service technician to inspect the appliance
and to replace any part of the control system and any gas control
which has been under water.
IF THE UNIT IS EXPOSED TO THE FOLLOWING, DO NOT OPERATE
HEATER UNTIL ALL CORRECTIVE STEPS HAVE BEEN MADE BY A
QUALIFIEDSERVICEMAN.
1. EXTERNAL FIRE.
2. DAMAGE.
3. FIRING WITHOUTWATER.
4. SOOTING.
CHEMICALVAPOR CORROSION
DANGER
CORROSION OFTHE FLUEAND VENT SYSTEM MAY OCCUR IFAIR
FOR COMBUSTION CONTAINS CERTAIN CHEMICALVAPORS. SUCH
CORROSION MAY RESULT IN FAILUREAND RISK OFASPHYXIATION.
Spray can propellants, cleaning solvents, refrigerator and air
conditioning refrigerants, swimming pool chemicals, calcium and
sodium chloride (water softener salt), waxes, and process
chemicals are typical compounds which are potentially corrosive.
Do not store products of this sort near the heater. Also, air which
is brought in contact with the heater should not contain any of
these chemicals. If necessary, uncontaminated air should be
obtained from remote or outside sources. The limited warranty is
voided when failure of water heater is due to a corrosive
atmosphere. (Refer to the limited warranty for complete terms and
conditions.)
IMPROPERCOMBUSTION
DANGER
ATTICAND/OREXHAUSTFANSOPERATING ONTHEPREMISESWITHA
WATERHEATERCANRESULTINCARBONMONOXIDEPOISONINGAND
DEATH.
OPERATIONOFTHESEFANSCANPRODUCEANEGATIVEDRAFTINTHE
AREA OF THE WATER HEATER PREVENTING THE PRODUCTS OF
COMBUSTIONFROM EXHAUSTINGTHROUGHTHECHIMNEYORVENTPIPE.
The venting of the water heater should be inspected by a qualified service
technician at the time of installation and periodically thereafter to ensure
a down-draft condition does not exist.
DONOTOBSTRUCTTHEFLOWOFCOMBUSTIONANDVENTILATINGAIR.
ADEQUATEAIRFORCOMBUSTIONANDVENTILATIONMUSTBEPROVIDED
FORSAFEOPERATION.
EXTENDED NONUSE PERIODS
DANGER
HYDROGEN GAS CAN BE PRODUCED IN A HOT WATER SYSTEM

6
foot of air. Therefore, the heater input rate should be reduced at high
altitudes for satisfactory operation with the reduced oxygen supply.
Failure to make this reduction 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 (610 m). 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 120,000
Btuh (35 Kwh) at sea level, to rate the heater at 4000 feet (1219 m),
you subtract 4 (once for each thousand feet) x 04 (4% input reduction)
x 120,000 (original rating) from the original rating. Therefore, to
calculate the input rating at 4,000 feet (121.9 m): 4 x .04 x 120,000 =
19,200 Btuh (5.6 Kwh), 120,000 (35 Kwh) - 19,200 (5.6 Kwh) = 100,800
Btuh (29.4 Kwh). At 6000 feet (1829 m) the correct input rating should
be 91,200 Btuh (26.7 Kwh).
Field conversion is not permitted.
FEATURES
THE ELIMINATOR
(SELF-CLEANING SYSTEM)
These units include The Eliminator (Self-Cleaning System) installed in
the front water inlet, see Figure 2. The Eliminator must be oriented
correctly for proper function. There is a marked range on the pipe
nipple portion of the Eliminator, that must be aligned with the top of the
inlet spud. A label above the jacket hole has an arrow that will point to
the marked portion of the pipe nipple if the orientation is correct. If the
arrow does not point within the marked range on the pipe nipple,
adjust the pipe nipple to correct. A pipe union is supplied with the
Eliminator to reduce the probability of misaligning the Eliminator
accidentally while tightening the connection to the inlet water supply
line. Improper orientation of the Eliminator can cause poor performance
of the heater and can significantly reduce outlet water temperatures
during heavy draws.
FIGURE1
HIGH LIMIT SWITCH (E.C.O.)
The dual bulb controller contains the high limit (energy cutoff) sensor,
see Figure 2. The high limit switch interrupts main burner gas flow
should the water temperature reach 205°F (96°C).
In the event of high limit switch operation, the appliance cannot be
restarted unless the water temperature is reduced by at least 20°F
(11°C) and the high limit reset button on front of limit control is depressed,
see Figure 2.
Continued manual resetting of high limit control, preceded by higher
than usual water temperature is evidence of high limit switch operation.
The following is a possible reason for high limit switch operation.
• A malfunction in the thermostatic controls could allow the gas valve
to remain open causing water temperature to exceed the
thermostat setting. The water temperature would continue to rise
until high limit switch operation.
Contact your dealer or servicer if continued high limit switch operation
occurs.
DUAL-BULB THERMOSTAT
(SHOWN AT TOP WITH COVER ONAND AT BOTTOM
WITH COVER REMOVED)
FIGURE 2
Continued pilot outage preceded by higher than usual water temperature
is evidence of high limit switch operation. Contact your dealer or
servicer to determine the reason for operation.
CIRCULATING PUMP
A circulating pump is used when a system requires a circulating
loop or there is a storage tank used in conjunction with the heater.
Refer to the piping diagrams in this manual for electrical hookup
information and install in accordance with the current version of
the National Electric Code ANSI/NFPANo. 70.
Only all bronze circulators are used with commercial water heaters.
Although circulators are oiled and operated by the manufacturer some
circulators must be oiled again before operating. Please refer to
manufacturer’s instructions.
DISHWASHING MACHINEREQUIREMENT
These appliances meet the National Sanitation Foundation Standard for
sanitary installations when used with the following leg kits, Part No’s.
6570-0 and 6570-7.
All dishwashing machines meeting the National Sanitation Foundation
requirements are designed to operate with water flow pressures

7
ROBERTSHAW 47484A PILOT SENSOR
ROBERTSHAW DERHC-S7C NATURAL 1" x 1" GAS VALVE
GASVALVE
The gas valve is used to supply the gas to the unit during heat up periods.
The ignition control module monitors the thermostat's call for heat and
sends a signal to the gas valve when to open to allow gas flow.
PRESSURESWITCH
The Blocked Outlet/Prover switch is set up to shut the unit off when a
pressure buildup in the exhaust vent pipe occurs. This switch is a
negative pressure switch that requires an increase in negative pressure
to change the electrical contacts from normally open to closed. The
switch is connected to the pressure tap connected to the housing of
the blower. When this switch prevents the unit from ignition, most
likely the exhaust is blocked by some means. Check for obstructions
in the exhaust vent terminal.
The Blocked Outlet/Prover switch has a second function. It is provided
on the heater to verify that the fan is operating. When the fan increases
in negative pressure, the electrical contacts close signaling that the
blower is operational and is at peak performance. The controller
requires that the electrical contacts on the switch close before it will
allow the burners to operate.
MPL 9300VO AIR PRESSURE SWITCH
between 15 and 25 psi (103 kPa and 173 kPa). Flow pressures above 25
psi (173 kPa), or below 15 psi (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 180°F (82°C) line to the
dishwashing machine, and should be adjusted to deliver water between
these limits.
The National Sanitation Foundation also recommends circulation of 180°F
(82°C) water. Where this is done, the circulation should be very gentle so
that it does not cause any unnecessary turbulence inside the water
heater. The circulation should be just enough to provide 180°F (82°C)
water at the point of takeoff to the dishwashing machine. Adjust flow by
means of the plug cock in the circulating line.
FIGURE 3
ROBERTSHAW SP715AIGNITION CONTROL MODULE
NATURAL GAS MODEL
ELECTRONICIGNITION CONTROL
Each heater is equipped with an ignition control module (See figure 3
above). The solid state ignition control ignites the pilot burner gas by
creating a spark at the pilot assembly. Pilot gas is ignited and burns
during each running cycle. The main burner and pilot gases are cut off
during the OFF cycle. Pilot operation is proven by the pilot sensor.
Main burner ignition will not occur if the pilot sensor does not first
sense pilot operation.
PILOTASSEMBLY
The pilot assembly is mounted between the two middle burner
assemblies in the combustion chamber. The ignition sequence begins
with the ignition module sending voltage to the sparker located on the
front side of the pilot hood. Pilot gas flow is initiated after the sparker
begins to spark. The spark across the pilot gas flow ignites the pilot
gas. Once the pilot gas is ignited, the flame sensor senses the flame
through flame rectification (which means that the module's signal
changes from an AC current to a DC current because the current can
now flow through the flame to the pilot hood which is grounded to the
unit). Once the sensor senses flame, the signal is sent back to the
module to open up the gas valve for the main burners.
ROBERTSHAW #6S24-6 PILOT ASSEMBLY

8
STEPDOWNTRANSFORMER
The controls system utilizes a 120/24 VAC step down transformer.
Most of the control system utilizes 24 VAC for operation. See wiring
diagram for those components utilizing 24 VAC and 120 VAC.
P120/24 VAC STEP DOWN TRANSFORMER
BURNERTRAYASSEMBLY
The appliance is equipped with a user friendly burner tray assembly.
The assembly consists of a burner tray for mounting the burners,
manifold and orifices along with the gas valve and pilot assembly. It
can be easily removed by sliding the assembly in and out like a drawer
due to slide mounts in the combustion chamber.
BURNER TRAYASSEMBLY- NATURAL
BURNER TRAY
The burner tray holds the burners in place and is used to slide the
entire assembly into the combustion chamber.
BURNERTRAY
BURNER
The appliance is equipped with 8 burners mounted in a burner tray
assembly. The burners are tubular in design with two rows of small slit
burner ports. The natural gas burners are made of aluminized steel and
the LP version is a stainless steel material.
TUBULARBURNERASSEMBLY
BURNERORIFICE
The burner orifice regulates the input to the main burners.
BURNERORIFICE
BLOWER ASSEMBLY
The blower assembly functions by pulling in air from the outside of the
unit to supply the main burners located in the combustion chamber for
proper combustion. The blower pulls the air through the combustion
chamber and flue tubes where the flue gases then exit the exhaust vent.
FASCO BLOWER ASSEMBLY

9
HIGH LIMIT SWITCH
The surface mounted high limit switch monitors the flue gases escaping
through the blower assembly to ensure the temperatures do not exceed
the rating for the CPVC/PVC vent pipe utilized on the venting.
FIGURE 4
HIGH LIMIT SWITCH
SHROUDASSEMBLY
The shroud assembly protects the top of the appliance where the blower
and junction box are located.
SHROUDASSEMBLY
TEMPERATUREAND PRESSURE RELIEF VALVE
The temperature and pressure relief valve is a mechanical valve that
will open when the temperature or pressure in the tank exceeds
safe limits.
TEMPERATUREAND PRESSURERELIEFVALVE
DRAIN VALVE
Thedrainvalveisusedtodraintheunitofwater for servicing or replacement.
DRAIN VALVE
INSTALLATION INSTRUCTIONS
REQUIREDABILITY
INSTALLATIONORSERVICEOFTHISWATERHEATERREQUIRESABILITY
EQUIVALENT TO THAT OF A LICENSED TRADESMAN IN THE FIELD
INVOLVED. PLUMBING, AIR SUPPLY, VENTING, GAS SUPPLY AND
ELECTRICALWORKAREREQUIRED.
WARNING
FAILURETOFOLLOWTHESEINSTRUCTIONSCAN RESULT IN SERIOUS
PERSONALINJURYORDEATH.
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 MAINTENANCE section for details of tank clean out procedure.
LOCATING THE HEATER
When installing the heater, consideration must be given to proper
location with adequate air supply and as centralized with the piping
system as possible.
WARNING
THEREISARISK IN USING FUELBURNINGAPPLIANCES SUCHAS GAS
WATER HEATERS IN ROOMS, GARAGES OR OTHER AREAS WHERE
GASOLINE,OTHERFLAMMABLELIQUIDSORENGINEDRIVENEQUIPMENT
OR VEHICLESARE STORED, OPERATED OR REPAIRED. FLAMMABLE
VAPORS ARE HEAVY AND TRAVEL ALONG THE FLOOR AND MAY BE
IGNITEDBYTHEHEATER’SPILOTOR MAINBURNERFLAMESCAUSING
FIREOREXPLOSION. SOMELOCALCODESPERMITOPERATIONOFGAS
APPLIANCES IN SUCH AREAS IFTHEYARE INSTALLED 18” OR MORE
ABOVETHE FLOOR. THISMAYREDUCETHERISKIF LOCATIONINSUCH
ANAREACANNOTBEAVOIDED.
DONOTINSTALLTHISWATERHEATERDIRECTLYONACARPETEDFLOOR. A
FIREHAZARDMAYRESULT. Insteadthewaterheatermustbeplacedonametal
or wood panel extending beyond the full width and depth by at least 3 inches (7.6
cm) in any direction. If the heater is installed in a carpeted alcove, the entire floor
shallbecoveredbythepanel. Also,seetheDRAINREQUIREMENTS.
THEHEATERSHALLBELOCATEDORPROTECTEDSOITISNOTSUBJECT
TOPHYSICALDAMAGE BYAMOVING VEHICLE.
WARNING
FLAMMABLE ITEMS, PRESSURIZED CONTAINERS OR ANY OTHER
POTENTIALFIRE HAZARDOUSARTICLESMUSTNEVERBEPLACEDON
ORADJACENT TOTHE HEATER. OPEN CONTAINERS OR FLAMMABLE
MATERIALSHOULDNOTBESTOREDORUSEDINTHESAMEROOMWITH
THEHEATER.THEHEATERMUSTNOTBELOCATEDINANAREAWHEREIT
WILLBESUBJECTTO FREEZING.LOCATE IT NEARAFLOORDRAIN. THE
HEATERSHOULDBELOCATEDINANAREAWHERELEAKAGEFROMTHE
HEATERORCONNECTIONSWILLNOTRESULTINDAMAGETOTHEADJACENT
AREAORTOLOWERFLOORSOFTHESTRUCTURE.
WHENSUCHLOCATIONSCANNOTBEAVOIDED,ASUITABLEDRAINPAN
SHOULDBEINSTALLEDUNDERTHEHEATER. Suchpansshouldbefabricated
with sides at least 2" (5 cm) deep, with length and width at least 2" (5 cm)
greater than the diameter of the heater and must be piped to an adequate
drain. The pan must not restrict combustion air flow.
For appliance installation locations with elevations above
2000 feet (610 m), refer to HIGH ALTITUDE INSTALLATIONS section of this
manual for input reduction procedure.
LEVELING
If the unit is not level, insert the bolts which were used in crating into the
legs to correct this condition.

10
CLEARANCES
The unit is approved for installation on combustible flooring in an alcove
when the minimum clearance to combustibles is maintained per Figure 6
and the table below.
ABCD
(RIGHTSIDE) (LEFTSIDE) (BACK) (CEILING)
0" (0cm) 0" (0cm) 0" (0cm) 12" (30.5 cm)
A service clearance of 24" (61 cm) should be maintained from serviceable
parts, such as relief valves, flue baffles, flue damper devices, thermostats,
cleanout openings or drain valves.
FIGURE 5
FIGURE 6
ALCOVE INSTALLATION (ACCEPTABLE)
An alcove suitable for the installation of a water heater is a restricted
section of a room not separated from the room by a door or partition and
which meets the minimum clearances for the water heater.
*When the ceiling height exceeds 8 feet (2.4 m), you are only allowed to
consider 8 feet (2.4 m) when calculating the total volume of the enclosure.
AIRREQUIREMENTS
REFERTOTHECURRENTEDITIONOFTHENATIONALFUELGAS CODE
ANSI Z223.1/NFPA 54. WARNING
KEEPAPPLIANCEAREACLEARANDFREEOFCOMBUSTIBLEMATERIALS,
GASOLINEANDOTHERFLAMMABLES,VAPORSAND LIQUIDS.
DONOTOBSTRUCTTHEFLOWOFCOMBUSTION ORVENTILATINGAIR.
WARNING
FORSAFEOPERATIONPROVIDEADEQUATEAIRFORCOMBUSTIONAND
VENTILATION. AN INSUFFICIENT SUPPLY OF AIR WILL CAUSE
RECIRCULATION OF COMBUSTION PRODUCTS RESULTING IN AIR
CONTAMINATIONTHATMAYBEHAZARDOUSTOLIFE. SUCHACONDITION
OFTENWILLRESULTINAYELLOW,LUMINOUSBURNERFLAME,CAUSING
CARBONINGORSOOTING OFTHECOMBUSTIONCHAMBER, BURNERS
ANDFLUETUBESAND CREATESARISK OFASPHYXIATION.
Where an exhaust fan is supplied in the same room with a heater, sufficient
openings for air must be provided in the walls. UNDERSIZED OPENINGS WILL
CAUSEAIRTOBEDRAWNINTOTHEROOMTHROUGHTHECHIMNEY,CAUSING
POORCOMBUSTION. SOOTINGMAYRESULTINSERIOUSDAMAGETOTHE
HEATERANDRISKOFFIREOREXPLOSION.
UNCONFINEDSPACE
Inbuildingsofconventionalframe,brick,orstoneconstruction, unconfined spaces
may provide adequate air for combustion, ventilation and draft hood dilution.
If the unconfined space is within a building of tight construction (buildings using
the following construction: weather stripping, heavy insulation, caulking, vapor
barrier,etc.),airforcombustion,ventilationanddrafthooddilutionmustbeobtained
fromoutdoors.Theinstallationinstructionsforconfinedspacesintightlyconstructed
buildings must be followed to ensure adequate air supply.
CONFINEDSPACE
When drawing combustion and dilution air from inside a conventionally
constructed building to a confined space, such a space shall be provided
with two permanent openings, ONE IN OR WITHIN 12 INCHES (30.5 cm)
OFTHE ENCLOSURE TOPAND ONE IN OR WITHIN 12 INCHES (30.5 cm)
OFTHE ENCLOSURE BOTTOM. Each opening shall have afreeareaofat
least one square inch per 1000 Btuh (2,225mm²/Kw) of the total input of
all appliances in the enclosure, but not less than 100 square inches (645
square cm).
If the confined space is within a building of tight construction, air for
combustion, ventilation, and draft hood dilution must be obtained from
outdoors. Whendirectlycommunicatingwiththeoutdoorsorcommunicating
with the outdoors through vertical ducts, two permanent openings, located
in the above manner, shall be provided. Each opening shall have a free
area of not less than one square inch per 4000 Btuh (8,900mm²/Kw) of the
total input of all appliances in the enclosure. If horizontal ducts are used,
each opening shall have a free area of not less than one square inch per
2000Btuh(4,450mm²/Kw)ofthetotalinputofallappliancesintheenclosure.
MECHANICALEXHAUSTINGOFROOMAIR
Where an exhaust fan is installed in the same room with a heater, sufficient
openings for air must be provided in the walls. UNDERSIZED OPENINGS
WILLCAUSEAIRTOBEDRAWNINTOTHEROOMTHROUGHTHEHEATER'S
VENTING SYSTEM, CAUSING POOR COMBUSTION AND/OR SOOTING
WHICHMAYRESULTIN SERIOUSDAMAGETOTHEHEATERANDRISKOF
FIREOREXPLOSION. ITCANALSOCREATEARISKOFASPHYXIATION.
COMBUSTION AIR AND EXHAUST
WARNING
WHEN DETERMINING THE INSTALLATION LOCATION FORAPOWER
DIRECTVENTWATER HEATER, SNOWACCUMULATIONAND DRIFTING
SHOULDBECONSIDEREDINAREAS WHERE APPLICABLE.
VENTINGCLEARANCES
VENTING THROUGH ANOUTSIDEWALL-CLEARANCES
• 1" (2.5 cm) clearance for 4" or 6" PVC or CPVC piping from combustible
surfaces for outlet piping.
• 0" clearance for 4" or 6" PVC or CPVC piping from combustible surfaces
for inlet piping.
• 18" (46 cm) minimum in all directions from any obstruction, such as a wall,
that may interfere.
• 18" (46 cm) minimum from the ground and 9" from ceiling overhangs.
See Figure 7.
• The Power Direct Vent outlet terminal shall terminate a least 36" (91 cm)
above any forced air inlet located within 10 feet. See Figure 8.
• The Power Direct Vent outlet terminal shall terminate at least 36" (91 cm)
below, 36" (91 cm) horizontally from or 18" (46 cm) above any door,
window or gravity air inlet into the building. See Figure 8.
• 18" (46 cm) minimum from other natural draft (gravity) direct vent, power
vent or power direct vent appliance inlet and/or outlet vent(s) when directly
above or 135° to either side of center line. See Figure 9.
• 36" (91 cm) minimum from any appliance inlet and / or outlet vents when
directly below or 45° to either side of center line. See Figure 9.
• Vent termination must not be within 4 feet of any items such as gas
meters, gas valves or other gas regulating equipment.
• The venting system must be installed in a manner which allows inspection
of the installation of the venting pipes and joints as well as periodic
inspection after installation as required by ANSI Standards.

11
FIGURE 9
WIRE FENCE
When the water heater outlet terminal is low enough to be touched
accidentally, or is accessible to small children, a wire mesh chain link
fence (as shown in Figure 9) may be used. Care should be taken to
maintain adequate ventilation around the outlet terminal. If a chain link
fence is installed, it must not be used as a storage area for items that
may block proper ventilation.
FIGURE 9
WARNING
THELOCATIONSELECTEDMUSTPROVIDECLEARANCESFORSERVICING
ANDPROPEROPERATIONOFTHEWATERHEATER.
WARNING
VENTTERMINATIONMUSTNOTBE WITHIN4FEETOFANYITEMSSUCHASGAS
METERS,GASVALVESOROTHERGASREGULATINGEQUIPMENT.
WARNING
FAILURETOHAVEREQUIRED CLEARANCESBETWEENWATERHEATER
ANDCOMBUSTIBLEMATERIALWILLRESULTINAFIREHAZARD.
FIGURE 7
FACTS TOCONSIDERABOUT THE LOCATION
VENTING THROUGH ROOF-CLEARANCES
• 1" (2.5 cm) clearance for 4" or 6" PVC or CPVC piping from
combustible surfaces for outlet piping.
• 0" clearance for 4" or 6" PVC or CPVC piping from combustible
surfaces for inlet piping.
• The Power Direct Vent inlet and outlet terminals shall terminate at
least 18" (46 cm) above the roof surface. See Figure 10.
• The venting system must be installed in a manner which allows
inspection of the installation of the venting pipes and joints as well as
periodic inspection after installation as required by ANSI Standards.
FIGURE 8 - DIRECT VENT TERMINAL CLEARANCES - US INSTALLATION

12
FIGURE10
WATER PIPING
WARNING
HOTTER WATER CAN SCALD: WATER HEATERSARE INTENDED TO
PRODUCE HOT WATER. WATER HEATED TO ATEMPERATURE WHICH
WILL SATISFY CLOTHES WASHING, DISH WASHING, AND OTHER
SANITIZING NEEDS CAN SCALDAND PERMANENTLYINJURE YOU
UPON CONTACT. SOME PEOPLE ARE MORE LIKELY TO BE
PERMANENTLY INJURED BY HOT WATER THAN OTHERS. THESE
INCLUDE THE ELDERLY, CHILDREN, THE INFIRM, OR PHYSICALLY/
MENTALLY HANDICAPPED. IF ANYONE USING HOT WATER IN YOUR
HOME FITS INTO ONE OF THESE GROUPS OR IF THERE IS A LOCAL
CODE OR STATE LAW REQUIRINGA CERTAIN TEMPERATURE WATER
AT THE HOT WATER TAP, THEN YOU MUST TAKE SPECIAL
PRECAUTIONS. IN ADDITION TO USING THE LOWEST POSSIBLE
TEMPERATURE SETTING THAT SATISFIES YOUR HOT WATER NEEDS,
A MEANS SUCH AS A MIXING VALVE, SHOULD BE USED AT THE
HOT WATER TAPS USED BY THESE PEOPLE OR AT THE WATER
HEATER. MIXING VALVES ARE AVAILABLE AT PLUMBING SUPPLY
OR HARDWARE STORES. FOLLOW MANUFACTURERS
INSTRUCTIONS FOR INSTALLATION OF THE VALVES. BEFORE
CHANGING THE FACTORY SETTING ON THE THERMOSTAT, READ
THE "TEMPERATURE REGULATION" SECTION IN THIS MANUAL.
This water heater shall not be connected to any heating systems or
component(s) used with a non-potable water heating appliance.
If a water heater is installed in a closed water supply system, such as
one having a back-flow preventer, check valve, water meter with
check valve, etc... in the cold water supply, means shall be provided
to control thermal expansion. Contact the water supplier or plumbing
contractor on how to control this situation.
NOTE: To protect against untimely corrosion of hot and cold
water fittings, it is strongly recommended that dielectric
unions or couplings be installed on this water heater when
connected to copper pipe.
NOTE: If using copper tubing, solder tubing to an adapter
before attaching the adapter to the cold water inlet connection.
Do not solder the cold water supply line directly to the cold
water inlet. It will harm the dip tube and damage the tank.
WARNING
IF A WATER HEATER IS INSTALLED IN CONJUNCTION WITH A
SEPARATE STORAGE VESSEL, THE STORAGE VESSEL MUSTALSO
BE EQUIPPED WITH A TEMPERATURE-PRESSURE RELIEF VALVE
COMPLYING WITH THE STANDARD FOR RELIEF VALVES AND HOT
WATER SUPPLY SYSTEMS, ANSI Z21.22. THE HOURLY RATED
TEMPERATURE STEAM BTU DISCHARGE CAPACITY OF THE
TEMPERATURE-PRESSURE RELIEF VALVE(S) SHALL NOT BE LESS
THAN THE COMBINED BTU INPUT TO THE WATER HEATER(S)
SUPPLYING WATER TO THE STORAGE VESSEL(S).
THERMOMETERS (NotSupplied)
Thermometers should be obtained and field installed as shown in the
installation diagrams.
Thermometers are installed in the system as a means of detecting the
temperature of the water in the appliance.
TEMPERATURE-PRESSURE RELIEF VALVE
This water heater is equipped with a combination temperature-pressure
relief valve that complies with the standard for relief valves and automatic
gas shutoff devices for hot water supply system, ANSI Z21.22. FOR
SAFE OPERATION OF THE WATER HEATER, THE RELIEF VALVE(S)
MUST NOT BE REMOVED OR PLUGGED.
ASME ratings cover pressure relief capacities. A.G.A. ratings cover
release rate with temperature actuation.
In addition to the appliance relief valve, each remote storage tank which
may be used in conjunction with this appliance shall also be installed with
a properly sized, rated and approved combination temperature (ANSI)
and pressure (ASME) relief valve(s).
WARNING
THE PURPOSE OF RELIEF VALVE IS TO AVOID EXCESSIVE
PRESSURE OR TEMPERATURE INTO THE STEAM RANGE, WHICH
MAY CAUSE SCALDING AT FIXTURES, TANK EXPLOSION, SYSTEM
OR HEATER DAMAGE. NO VALVE IS TO BE PLACED BETWEEN THE
RELIEF VALVE AND TANK.
Your local code authority may have other specific relief valve
requirements.
A DRAIN LINE MUST BE CONNECTED TO THE RELIEF VALVE TO
DIRECT DISCHARGE TO A SAFE LOCATION TO AVOID SCALDING
OR WATER DAMAGE. THIS LINE MUST NOT BE REDUCED FROM
THE SIZE OF THE VALVE OUTLET AND MUST NOT CONTAIN VALVES
OR RESTRICTIONS NOR SHOULD IT BE LOCATED IN FREEZING
AREAS. DO NOT THREAD OR CAP THE END OF THIS LINE.
RESTRICTED OR BLOCKED DISCHARGE WILL DEFEAT THE PURPOSE
OF THE VALVE AND IS UNSAFE. DISCHARGE LINE SHALL BE
INSTALLED TOALLOW COMPLETE DRAINAGE OF BOTH THE VALVE
AND LINE.
See SERVICE INFORMATION section for procedure and
precautions.
WARNING
THE TEMPERATURE-PRESSURE RELIEF VALVE MUST BE MANUALLY
OPERATED AT LEAST ONCEA 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 MAYBE 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, AND REPLACE
THE TEMPERATURE -PRESSURE RELIEF VALVE WITH ANEW ONE.

13
FILLING THE WATER HEATER
CAUTION
NEVER USE THIS WATER HEATER UNLESS IT IS COMPLETELY FILLED
WITH WATER. TO PREVENT DAMAGE TO THE TANK, THE TANK MUST
BE FILLED WITH WATER. WATER MUST FLOW FROM THE HOT WATER
FAUCET BEFORE TURNING"ON"GAS TOTHEWATER HEATER.
To fill the water heater with water:
1. Close the water heater drain valve by turning the handle to the right
(clockwise). The drain valve is on the lower front of the water heater.
2. Open the cold water supply valve to water heater. NOTE: The cold water
supply valve must be left open when the water heater is in use.
3. To insure complete filling of the tank, allow air to exit by opening the
nearest hot water faucet. Allow water to run until a constant flow is
obtained. This will let air out of the water heater and the piping.
4. Check all new water piping for leaks. Repair as needed.
WIRING
You must provide all wiring of the proper size outside of the water
heater. You must obey local codes and electric company requirements
when you install this water heater.
If you are not familiar with electric codes and practices, or if you have
any doubt in your ability to connect the wiring to this water heater, contact
a local electrical contractor and/or the local electric utility.
WARNING
WATER HEATERS EQUIPPED FOR ONE TYPE VOLTAGE ONLY: THIS
WATER HEATER IS EQUIPPED FOR 110/120 VOLTS ONLY. DO NOT USE
THIS WATER HEATER WITH ANY VOLTAGE OTHER THAN THE ONE
SHOWNABOVE.FAILURETO USETHECORRECT VOLTAGECANCAUSE
PROBLEMS WHICH CAN RESULT IN DEATH, SERIOUS BODILY INJURY
OR PROPERTY DAMAGE. IF YOU HAVEANYQUESTIONS OR DOUBTS
CONSULT YOUR ELECTRIC COMPANY.
CAUTION
IF WIRING FROM THE FUSE BOX OR CIRCUIT BREAKER BOX WAS
ALUMINUMFORTHEOLD WATER HEATER, REPLACEITWITHCOPPER
WIRE. IF YOU WISH TO REUSE THE EXISTINGALUMINUM WIRE, HAVE
THE CONNECTION AT THE WATER HEATER MADE BY A LOCAL
ELECTRICALCONTRACTOR AND/OR THE LOCAL ELECTRIC UTILITY.
FIELD INSTALLED WIRING
1. Provide a way to easily shut off the electric power when working
on the water heater. This could be with a circuit breaker or fuse
block in the entrance box or a separate disconnect switch.
2. Install and connect a circuit directly from the main fuse or circuit
breaker box. This circuit must be per applicable codes and have its
own fuse or circuit breaker.
3. Standard 1/2" conduit openings have been made in the water heater
junction box for side or bottom conduit connection.
4. Use wire nuts and connect the power supply wiring to the wires inside the
water heater’s junction box. MINIMUM LINE VOLTAGE WIRE NO.14 AWG.
5. The water heater must be electrically "grounded" by the installer.
The unit will not operate unless it is properly grounded. A green
ground screw has been provided on the water heater's junction box.
Connect ground wire to this location. For complete grounding details and
all allowable exceptions, refer to local codes or in the absence of local
codes, with the National Electrical Code, ANSI/NFPA 70 (current edition).
6. Close the wiring junction box cover.

14
WIRINGDIAGRAMFORROBERTSHAWCONTROL
SYSTEM- NATURALGAS ONLY
NOTE: If any of the original wire as supplied with the water heater
must be replaced, it must be replaced with 105°C thermoplastic
AWM wire or its equivalent.
CAUTION
LABEL ALL WIRES PRIOR TO DISCONNECTION WHEN SERVICING
CONTROLS. WIRING ERRORS CAN CAUSE IMPROPER AND
DANGEROUS OPERATION. VERIFY PROPER OPERATION AFTER
SERVICING.
MINIMUM LINE VOLTAGE WIRE NO. 14 AWG

15
VENTING
WARNING
TO INSURE PROPER VENTING OF THIS GAS-FIRED WATER
HEATER, THE CORRECT VENT PIPE DIAMETER MUST BE
UTILIZED. ANY ADDITIONS OF OTHER GAS APPLIANCES ON
VENT WITH THIS WATER HEATER ARE PROHIBITEDAS THEY
WILLADVERSELYAFFECT THE OPERATION OF THE WATER
HEATER.
WARNING
OBSTRUCTED OR DETERIORATED VENT SYSTEMS MAY
PRESENT SERIOUS HEALTH RISK ORASPHYXIATION.
WARNING
THE VENT PIPE FROM THE WATER HEATER MUST BE 4"
DIAMETER (16" OR 41 CM MIN. AND UP TO 45' OR 13.7 M
WITH ONE 90° ELBOW) OR 6" DIAMETER (45' OR 13.7 M
MIN. AND UP TO 110' OR 33.5 M WITH ONE 90° ELBOW)
AND MUST SLOPE UPWARD 1/8" (3 MM) PER FIVE LINEAR
FEET (1.5 M) FORANY HORIZONTAL RUN.
All vent gases must be completely vented to the outdoors of the
structure (dwelling).
WARNING
FAILURE TO HAVE REQUIRED CLEARANCES BETWEEN
WATER HEATER AND COMBUSTIBLE MATERIAL WILL
RESULT IN AFIRE HAZARD.
WARNING
BE SURE VENT PIPE IS PROPERLY CONNECTED TO PREVENT
ESCAPE OF DANGEROUS FLUE GASES WHICH COULD
CAUSE DEADLY ASPHYXIATION.
WARNING
CHEMICAL VAPOR CORROSION OF THE FLUE AND VENT
SYSTEM MAY OCCUR IFAIR FOR COMBUSTION CONTAINS
CERTAIN CHEMICAL VAPORS SPRAY CAN PROPELLANTS,
CLEANING SOLVENTS, REFRIGERATOR AND AIR
CONDITIONER REFRIGERANTS, SWIMMING POOL
CHEMICALS, CALCIUM AND SODIUM CHLORIDE, WAXES,
BLEACH AND PROCESS CHEMICALS ARE TYPICAL
COMPOUNDS WHICH ARE POTENTIALLYCORROSIVE.
Horizontal runs must be securely supported at 3 1/2 foot intervals and
vertical runs supported at 5 foot intervals.
VENTING THROUGH AN OUTSIDE WALL
Items supplied in the carton:
1. One 4" inlet PVC Schedule 40 - 45° vent cap with screen.
2. One 4" outlet CPVC Schedule 80 - 45° vent cap with screen.
3. Two 6" to 4" galvanized steel reducers.
4. Two wire screens to fit one each 6" PVC or CPVC 45° vent caps
(the 6" PVC or CPVC vent caps must be supplied locally).
5. One 4" long CPVC Schedule 40-6" diameter pipe section.
6. Four 4" and 6" wall collars.
All other PVC Schedule 40 or CPVC Schedule 40 or 80 piping and
fittings must be obtained locally.
TYPICALINSTALLATION-UPTO45'(13.7M)
Follow illustration above if making an immediate horizontal run of vent
off the blower fittings on top of the water heater.
For vent installations up to 110' (33.5 m), see page 16.
1. The water heater requires its own (separate) venting system.
2. Only 4" CPVC Schedule 40 piping and fittings are acceptable materials
for the first ten feet of the outlet vent system.
3. 4" PVC Schedule 40 or CPVC Schedule 40 or 80 piping and fittings are
acceptable materials for the inlet vent system and for the outlet vent
system after the first 10' (3 m). See vent length chart on page 16.

16
VENTING (CONT'D)
TYPICALINSTALLATION - UPTO110' (33.5 m)
Follow illustration above if making an immediate horizontal run of vent
off the blower fittings on top of the water heater.
1. The water heater requires its own (separate) venting system.
2. Only 6" CPVC Schedule 40 or 80 piping and fittings are acceptable
materials for the first ten feet of the outlet vent system.
3. 6" PVC Schedule 40 or CPVC Schedule 40 or 80 piping and fittings are
acceptable materials for the inlet vent system and for the outlet vent
system after the first ten feet. See vent length chart on this page.
VENTINGSYSTEM EXAMPLEINSTALLATIONSFOR
ALLMODELS
The vent piping cannot under any circumstances be run downhill.
THE VENT PIPING CAN BE INSTALLED AS FOLLOWS:
1. Horizontal runs require a minimum 1/8" (3 mm) rise per five feet.
2. The total vertical and horizontal run cannot exceed the maximum
length with number of 90° elbows as specified in the tables below.
If more elbows are required, the venting distance must be reduced
5' (1.5 m) for every 90° elbow:
MODEL MODEL NUMBER
100-400 100-400 OF
90° DEG.
4" DIA. VENT 6" DIA. VENT ELBOWS*
MAX. LENGTH MAX. LENGTH
45' (13.7 m) 110' (33.5 m) 1
40' (12 m) 105' (32 m) 2
35' (11 m) 100' (30.5 m) 3
30' (9 m) 95' (29 m) 4
25' (7.6 m) 90' (27.4 m) 5
20' (6 m) 85' (26 m) 6
15' (4.6 m) 80' (24.4 m) 7
10' (3 m) 75' (23 m) 8
*NOTE: Two 45° elbows are equivalent to one 90° elbow. One 90°
elbow equals 5' (1.5 m) equivalent vent length.

17
3. Minimum vent length is 18" (46 cm) when 4" pipe is used and 45'
(13.7 m) when 6" pipe is used.
CEMENTINGPVCORCPVCPIPEANDFITTINGS
Read and observe all safety information printed on primer, cleaner,
and cement containers.
DANGER
PRIMER,CLEANER,ANDCEMENTSAREEXTREMELYFLAMMABLE.
THEYARE HARMFUL OR FATALIF SWALLOWED.THEVAPORS
AREHARMFUL.THEYMAYIRRITATEEYESANDSKINANDCANBE
ABSORBEDTHROUGHTHESKIN.
CAUTION
ALWAYS STORE PRIMERS, CLEANER, AND CEMENTS IN
COOL, DRY, WELL VENTILATED PLACES. DO NOT STORE
THEM NEAR HEAT, SPARKS, OR FLAMES. KEEP CONTAINERS
CLOSED. USE THEM IN WELL VENTILATED AREAS. WEAR
IMPERVIOUS CLOTHING WHILE HANDLING. DO NOT SMOKE,
EAT, OR DRINK WHILE HANDLING. WASH THOROUGHLY
AFTER HANDLING AND BEFORE EATING. WEAR EYE
PROTECTION WHEN HANDLING. IF SWALLOWED, DRINK
WATER, DO NOT INDUCE VOMITING,AND CALLAPHYSICIAN
OR POISON CONTROL CENTER IMMEDIATELY. IF INHALED,
GET FRESH AIR AND SEEK MEDICAL ATTENTION IF ILL
FEELINGS PERSIST. IN CASE OF EYE AND SKIN CONTACT,
IMMEDIATELY FLUSH WITH PLENTY OF WATER FOR 15
MINUTES AND SEEK MEDICALATTENTION IF IRRITATION
PERSISTS. KEEP OUT OF REACH OF CHILDREN.
All primers, cleaners, and cements must meet all local codes and applicable
standards of the American Society For Testing Materials Standards.
Before using primers, cleaners, and cements, stir or shake, making sure
contents are liquid. Do not use if found to be lumpy or jellylike.
1. Cut pipe ends squarely removing all burrs and dirt.
2. Dry fit pipe and fittings to be connected for proper fit.
3. Clean pipe and fitting with a primer/cleaner.
4. Apply a thin coat of cement to fitting, avoiding puddling inside.
5. Apply a liberal coat of cement to pipe leaving no voids.
6. QUICKLY assemble parts while cement is fluid! If you wait too long,
recoat pipes.
7. Push pipe completely into socket of fitting, turning as it goes until it
bottoms.
8. Hold pipe and fitting together for 30 seconds. Then carefully clean off
excess with a cloth. Allow connections a sufficient time to cure before
disturbing.
9. Remember that vent pipes must be adequately and securely
supported.
APPROXIMATE SETTING TIME FOR 2 1/2" TO 6" PIPE JOINTS
MOVEMENT COMPLETE
OFJOINT SET
90°F to 150°F 3/4 hr. 8 hrs.
50°F to 90°F 1 hr. 15 hrs.
0°F to 50°F 1 1/3 hr. 18 hrs.
VENTPIPESEPARATION
The inlet and outlet vent pipes must be separated by a minimum distance of
10 1/2" (27 cm) with 4" vent, 12" (30.5 cm) with 6" vent and up to 24"
maximum.
NOTE: Inlet and outlet vent pipes from multiple power direct vent
water heaters must be separated from adjacent heater vent pipes
by a minimum of 10 1/2" (27 cm) with 4" vent or 12" (30.5 cm) with
6" vent.
CUTTINGOPENINGTHROUGHANOUTSIDEWALLAND COLLAR
INSTALLATION
After reading the manual and you have determined the location of the
opening in the wall, (using the drawing below), cut one 4 1/2" (11 cm)
diameter (for 4" vent pipe) or 6 1/2" (16.5 cm) diameter (for 6" vent pipe)
hole for the inlet vent piping and one 6 1/2" (16.5 cm) diameter (for 4" vent
pipe) or 8 1/2" (21.6 cm) diameter (for 6" vent pipe) hole for the outlet vent
piping through an exterior wall.
NOTE: When determining location of the openings in the outside
wall allow for the 1/8" (3 mm) rise per 5' (1.5 m) that has taken
place in the horizontal run.

18
The 4" or 6" PVC Schedule 40 or CPVC Schedule 40 or 80 vent pipes can
be run from the water heater through the wall or from the wall to the
water heater, whichever is most convenient. The vent pipes must extend
a minimum of 1 1/2" (3.8 cm) through the exterior wall. Extending the vent
caps as far as possible from the surface of the exterior wall will help
minimize discoloration of the wall. Note that the inside flue mounting
adaptors must be slipped over the vent piping before locating the pipe
through the wall. Before securing the inside and outside collars to the
wall, use a silicone sealer between pipe and opening to insure a water
and air tight seal.
INSTALLATION SHOWING USE OF PVC OR CPVCPIPE FOR INLET
VENT PIPING:
Inlet piping through any type wall.
INSTALLATION SHOWING USE OF PVC OR CPVC PIPE FOR
OUTLETVENT PIPING:
Outlet vent piping showing 1" (2.5 cm) clearance through a wall of
combustible construction.
CONNECTINGVENTTOBLOWER - 4" VENTPIPING
1. If making an immediate horizontal run of vent off the blower, the 6"
(15 cm) to 4" galvanized steel reducer and a PVC Schedule 40
street elbow are required for the inlet pipe, and the 6" to 4" reducer
and two CPVC Schedule 40 or 80 street elbows are required for
the outlet vent. Place the elbows in the required direction on the
reducers, and using 3 sheet metal screws each, attach the reducers
to the blower inlet and outlet collars and then attach the elbows to
the reducers.
2. If there is to be a vertical run of vent from the blower, the 6" to 4"
galvanized steel reducer must be attached to the venting hood collar
and then the PVC inlet pipe can be attached to the reducer using 3
sheet metal screws for each connection. A 6" to 4" reducer must be
attached to the blower outlet collar. Next, an outlet CPVC Schedule 40
or 80 street elbow is attached to the reducer using 3 sheet metal
screws for each connection. The CPVC Schedule 40 or 80 outlet
piping (for the first 10' or 3.05 cm) is then cemented to the street
elbow.

19
CONNECTINGVENTTOBLOWER - 6" VENTPIPING
1. If making an immediate horizontal run of vent off the blower, a 7 1/
4" (18.4cm) min. long PVC Schedule 40 pipe section and an elbow
are required for the inlet pipe.A4" min. long CPVC Schedule 40 pipe
section (supplied), one CPVC Schedule 40 or 80 regular elbow and
one CPVC Schedule 40 or 80 street elbow are required for the
outlet vent.
2. If there is to be a vertical run of vent from the blower, the PVC Schedule
40 inlet pipe must be attached to the venting hood collar. A 4" min. long
CPVC Schedule 40 pipe section (supplied) must be attached to the
blower outlet collar using three sheet metal screws. A CPVC Schedule
40 or 80 elbow is then cemented on to the end of the 4" pipe section.
CPVC Schedule 40 or 80 pipe (for the first ten feet) is then cemented to
the upturned elbow.
VENTINGTHROUGHAROOF
Items supplied in the carton:
1. One 4" inlet PVC Schedule 40 - 45° vent cap with screen.
2. One 4" outlet CPVC Schedule 80 - 45° vent cap with screen.
3. Two 6" to 4" galvanized steel reducers.
4. Two wire screens to fit one each 6" PVC or CPVC 45° vent caps (the 6"
PVC or CPVC vent caps must be supplied locally).
5. One 4" long CPVC Schedule 40 6" diameter pipe section.
6. Four 4" and four 6" wall collars.
All other PVC Schedule 40 or CPVC Schedule 40 or 80 piping and fittings
must be supplied locally.
1. The water heater requires its own (separate) venting system.
2. Only 4" or 6" CPVC Schedule 40 or 80 piping and fittings are acceptable
materials for the first ten feet of the outlet vent system.

20
gas control valve could result in a fire or explosion from
leaking gas.
WARNING
If the main gas line shutoff serving all gas appliances is used,
also turn “OFF” the gas at each appliance. Leave all gas
appliances shut off until the water heater installation is
complete.
CORRECTGASPIPESIZEFOR
WATERHEATERSOPERATING ON NATURALGAS
TOTAL INPUT DISTANCE TOMETER,INFEET
BTU/HR 30 60 90 120 150 180 210
300,000 1 1/4 1 1/4 1 1/4 1 1/2 1 1/2 1 1/2 1 1/2
400,000 1 1/4 1 1/2 1 1/2 1 1/2 2 2 2
Agas line of sufficient size must be run to the water heater. Consult the
currenteditionofNationalFuelGasCodeANSIZ223.1,alsoreferredtoas
NFPA54 andthegascompanyconcerningpipe size.
Theremustbe:
–Areadily accessible manualshutoffvalvein the gassupplylineserving
the water heater, and
–Adrip leg (sedimenttrap)aheadofthe gas controlvalvetohelp prevent
dirtand foreignmaterialsfrom entering thegas control valve.
–A flexible gas connector or a ground joint union between the shutoff
valve and control valve to permit servicing of the unit.
Be sure to check all the gas piping for leaks before lighting the water
heater. Useasoapy water solution,nota matchoropenflame. Rinseoff
soapy solution and wipe dry.
Wheninstalledatelevationsabove2,000'(610m),inputratingsshould be
reducedat therateof4 percentfor each 1,000'(305 m)above sea level.
WARNING
Theappliance anditsgas connection mustbe leak testedbefore
placing the appliance in operation.
WARNING
The appliance and its individual shutoff valve must be
disconnected from the gas supply piping system during any
pressure testing of that system at test pressures in excess of
1/2 pound per square inch (3.5kPa).
Theappliancemustbeisolatedfromthegassupplypipingsystem
byclosingitsindividualmanualshutoff valve during any pressure
testingof the gas supplypipingsystemat test pressuresequalto
or less than 1/2 pound per square inch (3.5kPa).
WARNING
Contaminants in the gas lines may cause improper operation
of the gas control valve that may result in fire or explosion.
3. 4" or 6" PVC Schedule 40 or CPVC Schedule 40 or 80 piping and
fittings are acceptable materials for the inlet vent system and for
the outlet vent system after the first ten feet. See vent length chart
below.
4. Itcannot be connected toexistingventpipingorchimney.
5. Itmustterminate vertically to the outdoors.
6. The total vertical and horizontal run cannot exceed the
maximum length with number of 90° elbows as specified in
the table below. If more elbows are required, the venting
distance must be reduced 5' (1.5 m) for every 90° elbow:
MODEL MODEL NUMBER
100-400 100-400 OF
90°DEG.
4"DIA. VENT 6" DIA.VENT ELBOWS*
MAX.LENGTH MAX.LENGTH
45' (13.7 m) 110' (33.5 m) 1
40' (12 m) 105' (32 m) 2
35' (11 m) 100' (30.5 m) 3
30' (9 m) 95' (29 m) 4
25' (7.6 m) 90' (27.4 m) 5
20' (6 m) 85' (26 m) 6
15' (4.6 m) 80' (24.4 m) 7
10' (3 m) 75' (23 m) 8
*NOTE: Two 45° elbows are equivalent to one 90° elbow. One 90°
elbow equals 5' (1.5 m) equivalent vent length.
7. Minimum vent length is 18 inches when 4" pipe is used and 45
feet when 6" pipe is used.
NOTE: See page 17 for instructions on cementing PVC or CPVC
pipe and fittings.
GAS PIPING
WARNING
Make sure the gas supplied is the same type listed on the
model rating plate. The inlet gas pressure must not exceed
10.5 in. water column (2.6kPa) for natural gas. The minimum
inlet gas pressure listed on the rating plate is for the purpose
of input adjustment.
WARNING
If the gas control valve is subjected to pressures exceeding
1/2 pound per square inch (3.5kPa), the damage to the