A.O. Smith BTL-120, BTL-154, BTL-180, BTL-198, BTL-199 Installation Manual
...
Instruction Manual
COMMERCIAL GAS WATER HEATERS
MODELS
BTL 120, 154, 180, 198, 199,
250(A), 275(A), 310(A), 366(A), 400(A)
500 Tennessee Waltz Parkway
Ashland City, TN 37015
INSTALLATION - OPERATION - SERVICE
- MAINTENANCE - LIMITED WARRANTY
Complies with SCAQMD Low NOx Rule 1146.2
Ultra Low NOx SERIES 200
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.
Thank you for buying this energy efcient water heater.
We appreciate your condence in our products.
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.
PLACE THESE INSTRUCTIONS ADJACENT TO HEATER AND NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.
PRINTED 0914 327502-005
TABLE OF CONTENTS
SAFE INSTALLATION, USE AND SERVICE.............................3
APPROVALS ............................................................................. 3
GENERAL SAFETY INFORMATION ......................................... 4
Precautions .......................................................................... 5
Grounding Instructions ......................................................... 5
Hydrogen Gas Flammable ................................................... 5
INTRODUCTION ....................................................................... 6
Abbreviations Used .............................................................. 6
Qualications........................................................................ 6
Preparing for the Installation ................................................ 6
FEATURES AND COMPONENTS ............................................6
Controls ................................................................................ 6
The Eliminator (self-cleaning system) .................................. 6
High Limit Switch.................................................................. 7
Electronic Ignition Control .................................................... 7
Blower/Burner Assembly ...................................................... 7
INSTALLATION CONSIDERATIONS ........................................ 8
Rough In Dimensions ........................................................... 8
Locating the Water Heater ................................................... 9
Clearances ........................................................................... 9
NSF Leg Kit ........................................................................ 10
Insulation Blanket ............................................................... 10
Hard Water ......................................................................... 10
Circulation Pumps .............................................................. 10
High Altitude Installations ................................................... 11
INSTALLATION REQUIREMENTS ......................................... 12
Gas Supply Systems .......................................................... 12
Gas Pressure Requirements .............................................. 12
Supply Gas Regulator ........................................................ 12
Power Supply ..................................................................... 12
Water Temperature Control and Mixing Valves .................. 12
Dishwashing Machines ......................................................13
Closed Water Systems ....................................................... 13
Thermal Expansion ............................................................ 13
Temperature-Pressure Relief Valve ...................................13
Combustible Material Storage ............................................ 14
Contaminated Air................................................................14
Air Requirements ...............................................................15
Unconned Space .............................................................. 15
Conned Space.................................................................. 15
Fresh Air Openings for Conned Spaces ........................... 16
Outdoor Air Through Two Openings ................................... 16
Outdoor Air Through One Opening .................................... 16
Outdoor Air Through Two Horizontal Ducts ........................ 16
Outdoor Air Through Two Vertical Ducts ............................ 17
Air From Other Indoor Spaces ........................................... 17
VENTING INSTALLATION ...................................................... 18
Venting ............................................................................... 18
Multiple Heater Manifold ....................................................18
WATER HEATER INSTALLATION ...........................................21
Water Line Connections ..................................................... 21
T&P Valve Discharge Pipe ................................................. 21
Installation Diagrams - Top Inlet/Outlet Usage ................... 22
Heater Wiring ..................................................................... 23
Gas Piping.......................................................................... 24
Gas Line Leak Testing ........................................................ 24
Purging ............................................................................... 24
START UP ............................................................................... 25
Prior to Start Up .................................................................25
Initial Start Up..................................................................... 25
Checking Venting ............................................................... 26
Checking the Input ............................................................. 26
Water Temperature Adjustment .......................................... 26
SEQUENCE OF OPERATION ................................................ 27
Lighting & Operating Label................................................. 27
Sequence of Operation Flow Chart .................................... 28
MAINTENANCE .....................................................................29
Venting System .................................................................. 29
Intake Air Screen ................................................................ 29
Temperature-Pressure Relief Valve Test ............................ 29
Anode Rod Inspection ........................................................ 29
Draining and Flushing ........................................................ 30
Periodic Removal of Lime Deposits from Tank Type Commercial
Water Heaters .................................................................... 30
Deliming Solvents ..............................................................30
Tank Cleanout Procedure................................................... 31
Deliming Using Flo-Jug Method ......................................... 31
SERVICE ................................................................................. 32
Ignition Control System ...................................................... 32
System Diagnostics............................................................ 32
Electrical Servicing ............................................................. 32
FOR YOUR INFORMATION .................................................... 33
Start Up Conditions ............................................................ 33
Operational Conditions....................................................... 33
TROUBLESHOOTING ............................................................34
WATER PIPING DIAGRAMS ................................................... 35
NOTES .................................................................................... 50
LIMITED WARRANTY ............................................................. 51
2
SAFE INSTALLATION, USE AND SERVICE
The proper installation, use and servicing of this water heater is extremely important to your safety and the safety of others.
Many safety-related messages and instructions 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 instructions throughout this manual. It is very important
that the meaning of each safety message is understood by you and others who install, use, or service this water heater.
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.
DANGER indicates an imminently
DANGER
WARNING
CAUTION
hazardous situation which, if not avoided,
will result in 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
CAUTION
All safety messages will generally tell you about the type of hazard, what can happen if you do not follow the safety message, and
how to avoid the risk of injury.
The California Safe Drinking Water and Toxic Enforcement Act requires the Governor of California to publish a list of substances
known to the State of California to cause cancer, birth defects, or other reproductive harm, and requires businesses to warn of
potential exposure to such substances.
WARNING: This product contains a chemical known to the State of California to cause cancer, birth defects, or other reproductive
harm. This appliance can cause low level exposure to some of the substances listed in the Act.
symbol indicates a potentially hazardous
situation which, if not avoided, could result in
property damage.
APPROVALS
3
GENERAL SAFETY INFORMATION
CAUTION
Fire or Explosion Hazard
Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this or any other appliance.
Avoid all ignition sources if you smell gas.
Do not expose water heater controls to excessive gas
pressure.
Use only the gas shown on the water heater rating label.
Maintain required clearances to combustibles.
Keep ignition sources away from faucets after extended
periods of non-use.
Read instruction manual before
installing, using or servicing
water heater.
Fire Hazard
For continued protection against
risk of fire:
Do not install water heater on
carpeted floor.
Do not operate water heater if
exposed to flooding or water damage.
Fire and Explosion Hazard
Use joint compound or Teflon tape
compatible with propane gas.
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.
Property Damage Hazard
All water heaters eventually leak.
•
Do not install without adequate drainage.
•
Electrical Shock Hazard
Turn off power to the water heater
•
before performing any service.
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 and Explosion Hazard
Do not use water heater with any gas
other than the gas shown on the rating
label.
Excessive gas pressure to gas valve can
cause serious injury or death.
Turn off gas lines during installation.
Contact a qualified installer or service
technician for installation and service.
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.
4
GENERAL SAFETY INFORMATION
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.
CAUTION
Improper installation, use and service may result
in property damage.
Do not operate water heater if 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.
Verify the power to the water heater is turned off before performing any service procedures.
GENERAL SAFETY INFORMATION
PRECAUTIONS
DO NOT USE THIS WATER HEATER IF ANY PART HAS BEEN
EXPOSED TO FLOODING OR WATER DAMAGE. Immediately
call a qualied service technician to inspect 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 corrective steps have been made by a qualified
service technician.
1. External re.
2. Damage.
3. Firing without water.
GROUNDING INSTRUCTIONS
This water heater must be grounded in accordance with the
National Electrical Code and/or local codes. These must be
followed in all cases.
This water heater must be connected to a grounded permanent
wiring system; or an equipment grounding conductor must
be run with the circuit conductors and connected to the
equipment grounding terminal or lead on the water heater,
see Figure 20.
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 can be produced 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
ammable. To reduce the risk of injury under these conditions,
it is recommended that a hot water faucet served by this water
heater be opened for several minutes 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 ow. THERE
SHOULD BE NO SMOKING OR OPEN FLAME NEAR THE
FAUCET AT THE TIME IT IS OPEN.
5
INTRODUCTION
Thank You for purchasing this water heater. Properly installed
and maintained, it should give you years of trouble free service.
ABBREVIATIONS USED
Abbreviations found in this Instruction Manual include :
• ANSI - American National Standards Institute
• ASME - American Society of Mechanical Engineers
• AHRI - Air-Conditioning, Heating, and Refrigeration Institute
• NEC - National Electrical Code
• NFPA - National Fire Protection Association
• UL - Underwriters Laboratory
• CSA - Canadian Standards Association
QUALIFICATIONS
Qualied Installer or Service Agency
Installation and service of this water heater requires ability
equivalent to that of a Qualied Agency (as dened by
ANSI below) in the eld involved. Installation skills such
as plumbing, air supply, venting, gas supply and electrical
supply are required in addition to electrical testing skills when
performing service.
ANSI Z223.1 2012 Sec. 3.3.85: “Qualied Agency” - “Any
individual, rm, corporation or company that either in person or
through a representative is engaged in and is responsible for (1)
the installation, testing or replacement of gas piping or (2) the
connection, installation, testing, repair or servicing of appliances
and equipment; that is experienced in such work; that is familiar
with all precautions required; and that has complied with all the
requirements of the authority having jurisdiction.”
If you are not qualied (as dened by ANSI above) and licensed
or certied as required by the authority having jurisdiction
to perform a given task do not attempt to perform any of the
procedures described in this manual. If you do not understand
the instructions given in this manual do not attempt to perform
any procedures outlined in this manual.
PREPARING FOR THE INSTALLATION
1. Read the "General Safety Information" section, pages 4-5 of
this manual rst and then the entire manual carefully. If you
don’t follow the safety rules, the water heater will not operate
properly. It could cause DEATH, SERIOUS BODILY INJURY
AND/OR PROPERTY DAMAGE.
This manual contains instructions for the installation, operation,
and maintenance of the gas-red water heater. It also contains
warnings throughout the manual that you must read and be
aware of. All warnings and all instructions are essential to the
proper operation of the water heater and your safety. Since
we cannot put everything on the rst few pages, RE AD THE
ENTIRE MANUAL BE FORE ATTEMPTING TO INSTALL OR
OPERATE THE WATER HEATER.
2. The installation must conform with these instructions and the
local code authority having jurisdiction. 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 or CAN/
CSA-B149.1 the Natural Gas and Propane Installation Code.
All documents are available from the Canadian Standards
Association, 8501 East Pleasant Valley Road, Cleveland, OH
44131. NFPA documents are also available from the National Fire
Protection Association, 1 Batterymarch Park, Quincy, MA 02269.
3. If after reading this manual you have any questions or do not
understand any portion of the instructions, call the local gas utility
or the manufacturer whose name appears on the rating plate.
4. Carefully plan the place where you are going to put the
water heater. Correct combustion, vent action, and vent pipe
installation are very important in preventing death from possible
carbon monoxide poisoning and res.
Examine the location to ensure the water heater complies with
the “Locating the Water Heater” section in this manual.
5. For California installation this water heater must be braced,
anchored, or strapped to avoid falling or moving during an
earthquake. See instructions for correct installation procedures.
Instructions may be obtained from California Ofce of the State
Architect, 400 P Street, Sacramento, CA 95814.
CONTROLS
FEATURES AND COMPONENTS
FIGURE 1.
THE ELIMINATOR (SELF-CLEANING SYSTEM)
These units include The Eliminator (Self-Cleaning System)
installed in the front water inlet, see Figure 2. The Eliminator inlet
tube can only be used in the front water inlet connection. Do not
install the Eliminator inlet tube in either the top or back inlet water
connection. 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.
6
Note: The Eliminator may have 1, 3 or 7 cross tubes.
ON
LIGHTS
FIGURE 2.
HIGH LIMIT SWITCH
The digital thermostat (Figure 3) contains the high limit (energy
cutout) switch. The high limit switch interrupts burner gas ow should
the water temperature reach 203°F (95°C).
In the event of high limit switch operation, the water heater cannot be
restarted unless the water temperature is reduced to approximately
120°F (49°C). The high limit reset button on the front of the control
then needs to be depressed.
Continued manual resetting of high limit control, preceded by higher
than usual water temperature is evidence of high limit switch operation.
Contact your dealer or service agent if continued high limit switch
operation occurs.
130
140
RESET
BUTT
BLOWER/BURNER ASSEMBLY
The fan-assisted combustion system includes a spark-to-pilot
igniter, 100% premix stainless steel burners, and prejets for input
rate and precision air/gas ratio control.
2-BURNER / BLOWER ASSEMBLY
(for Input of 199KBtu/H or Less)
LED
FUSE
DIGITAL THERMOSTAT
FIGURE 3.
ELECTRONIC IGNITION CONTROL
Each heater is equipped with an ignition control. The solid state
ignition control (Figure 4), ignites the burner by utilizing an
intermittent spark-to-pilot igniter. Spark and pilot gas ON until
lightoff or trial for ignition ends. If pilot fails to light, pilot gas and
spark OFF (100% shutoff). After 5 minutes delay, a new trial for
ignition is initiated. This sequence continues until lightoff or "Call
for Heat" is removed.
3-BURNER / BLOWER ASSEMBLY
(for Input of 250KBtu/H or Higher)
FIGURE 5.
The intake air screen is attached to the inlet of the combustion
blower. Inspect the intake air screen every six months. The intake
air screen should be cleaned of any buildup of debris or foreign
material.
IGNITION CONTROL
FIGURE 4.
7
INSTALLATION CONSIDERATIONS
ROUGH IN DIMENSIONS
FIGURE 6.
TABLE 1. ROUGH-IN-DIMENSIONS
MODEL DIM.
A 633/4 161.93 713/4 182.25 713/4 182.25
B 37 93.98 37 93.98 37 93.98
C 65 165.1 73 18542 73 18542
D 523/4 133.99 603/4 154.31 603/4 154.31
E 203/4 52.71 201/2 52.07 201/2 52.07
F 21 53.34 21 53.34 21 53.34
G 3/4 NPT 3/4 NPT 3/4 NPT
H 53 134.62 61 154.94 61 154.94
I 6 15.24 6 15.24 6 15.24
J 273/4 70.49 273/4 70.49 273/4 70.49
K 1 1/2 NPT 1 1/2 NPT 1 1/2 NPT
L
M - - 8 20.3 8 20.3
Approx. Shipping Weight STD 650 295 750 341 810 367
Approx. Shipping Weight ASME N/A N/A 800 363 860 390
BTL-120, 154, 180, 198 BTL-199, 250(A), 275(A) BTL-310(A), 366(A), 400(A)
inches cm inches cm inches cm
1 1/2 NPT 1 1/2 NPT 1 1/2 NPT
TABLE 2. RECOVERY CAPACITIES, BASED ON 80% THERMAL EFFICIENCY
Model
BTL-120
BTL-154
BTL-180
BTL-198
BTL-199
BTL-250(A)
BTL-275(A)
BTL-310(A)
BTL-366(A)
BTL-400(A)
Input
Input KwU.S.
Kbtuh
120 81 80 GPH 320 288 230 213 192 165 160 144 128 115 107 105 96 91 89 82
35 307 LPH
154 81 80 GPH 411 370 296 274 246 211 205 185 164 148 137 134 123 117 114 106
45 307 LPH
180 81 80 GPH 480 432 346 320 288 247 240 216 192 173 160 157 144 137 133 123
53 307 LPH
199 81 80 GPH 531 478 382 354 319 273 265 239 212 191 177 174 159 152 147 137
58 307 LPH
199 100 80 GPH 531 478 382 354 319 273 265 239 212 191 177 174 159 152 147 137
58 378 LPH
250 100 80 GPH 667 600 480 445 400 343 333 300 267 240 222 218 200 191 185 171
73 378 LPH
275 100 80 GPH 734 660 528 489 440 377 367 330 293 264 245 240 220 210 203 189
81 378 LPH
310 86 80 GPH 827 744 595 551 496 425 413 372 331 298 276 271 248 236 229 213
91 325 LPH
366 86 80 GPH 976 879 703 651 586 502 488 439 391 352 325 320 293 279 270 251
107 325 LPH
390 86 80 GPH
114 325 LPH
Gal.
Liters
°F 36 40 50 54 60 70 72 80 90 100 108 110 120 126 130 140
Eff. %
°C 20 22 28 30 33 39 40 44 50 56 60 61 67 70 72 78
1212 1091
1555 1399 1120 1037
1818 1636 1309 1212 1091
2009 1808 1447 1340 1206 1033 1005
2009 1808
2524 2272 1818 1683 1515 1298 1262 1136 1010
2777 2499 1999 1851 1666 1428 1388 1250 1111 1000
3130 2817 2254 2087 1878 1610 1565 1409 1252 1127 1043 1024
3696 3326 2661 2464 2217 1901 1848 1663 1478 1330 1232 1209 1109 1056 1023
1040
3938 3544 2835 2625 2363 2025 1969 1772 1575 1418 1313 1289 1181 1125 1091 1013
U.S. Gallons/hr and Liters/hr at Temperature Rise Indicated
872 808 727 623 606 545 485 436 404 397 364 346 336 312
933 800 777 700 622 560 518 509 466 444 431 400
935 909 818 727 654 606 595 545 519 503 467
904 804 723 670 658 603 574 556 517
1447
1340 1206 1033 1005
936 749 694 624 535 520 468 416 375 347 340 312 297 288 268
904 804 723 670 658 603 574 556 517
909 841 826 757 721 699 649
926 909 833 793 769 714
939 894 867 805
TABLE 3. GAS AND ELECTRICAL CHARACTERISTICS
Model Gas Type
120 THRU 275(A) Natural 3.5" W.C. (0.87 kPa) 14" W.C. (3.48 kPa) 120/60 <5
310(A) THRU 400(A) Natural 4.5" WC (1.12 KPA) 14" W.C. (3.48 kPa) 120/60 <5
Gas Supply Pressure
Minimum Maximum
8
Volts / Hz Amperes
950
LOCATING THE WATER HEATER
CAUTION
Property Damage Hazard
All water heaters eventually leak.
•
Do not install without adequate drainage.
•
When installing the heater, consideration must be given to
proper location. Location selected should be as close to the
stack or chimney as practicable, with adequate air supply and as
centralized with the piping system as possible.
Fire or Explosion Hazard
Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this or any other appliance.
Avoid all ignition sources if you smell gas.
Do not expose water heater controls to excessive gas
pressure.
Use only the gas shown on the water heater rating label.
Maintain required clearances to combustibles.
Keep ignition sources away from faucets after extended
periods of non-use.
Read instruction manual before
installing, using or servicing
water heater.
There is a risk in using fuel burning appliances such as gas
water heaters in rooms, garages or other areas where gasoline,
other ammable liquids or engine driven equipment or vehicles
are stored, operated or repaired. Flammable vapors are heavy
and travel along the oor and may be ignited by the heater's
igniter or main burner ames causing re or explosion. Some
local codes permit operation of gas appliances in such areas if
they are installed 18" or more above the oor. This may reduce
the risk if location in such an area cannot be avoided.
Do not install this water heater directly on a carpeted oor.
A re hazard may result. Instead the water heater must be
placed on a metal or wood panel extending beyond the full
width and depth by at least 3 inches in any direction. If the
heater is installed in a carpeted alcove, the entire oor shall
be covered by the panel.
The heater shall be located or protected so it is not subject to
physical damage by a moving vehicle.
Flammable items, pressurized containers or any other
potential fire hazardous articles must never be placed on
or adjacent to the heater. Open containers or flammable
material should not be stored or used in the same room with
the heater.
The heater must not be located in an area where it will be
subject to freezing.
Locate it near a floor drain. The heater should be located in
an area where leakage from heater or connections will not
result in damage to adjacent area or to the lower floors of
the structure.
When such locations cannot be avoided, a suitable drain pan
should be installed under heater. Such pans should be fabricated
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 restrict combustion air ow.
CLEARANCES
This water heater is approved for installation on combustible
ooring in an alcove with minimum clearance from combustion
construction as indicated in Figure 7 and Table 4.
In all installations the minimum combustible clearances from
vent piping shall be 6” (15.2 cm). Vent piping passing through a
combustible wall or ceiling must be a continuous run (no joints)
and retain 6” (15.2 cm) clearance unless an approved reducing
thimble is used.
When the water heater is installed directly on carpeting, the water
heater shall be installed on a metal or wood panel extending
beyond the full width and depth of the water heater by at least
3 in (76.2 mm) in any direction or, if the water heater is installed
in an alcove or closet, the entire oor shall be covered by the
panel. The panel must be strong enough to carry the weight of
the heater when full of water.
A service clearance of at least 24” (61 cm) should be maintained
from serviceable parts.
TABLE 4. MINIMUM CLEARANCES TO COMBUSTIBLE OR
NON-COMBUSTIBLE CONSTRUCTION
Model "A" Right Side "B" Left Side "C" Back "D" Ceiling
0" 0" 0" 12"
All
0 cm 0 cm 0 cm 30.5 cm
9
death. Always read and understand instruction manual.
NSF LEG KIT
FIGURE 7.
INSULATION BLANKET
Breathing Hazard - Carbon Monoxide Gas
Do not obstruct water heater air intake
with insulating blanket.
Gas and carbon monoxide detectors
are available.
Install water heater in accordance with
the instruction manual.
Breathing carbon monoxide can cause brain damage or
Insulation blankets are available to the general public for external
use on gas water heaters but are not necessary with these
products. The purpose of an insulation blanket is to reduce the
standby heat loss encountered with storage tank heaters. The
water heaters covered by this manual meet or exceed the Energy
Policy Act standards with respect to insulation and standby heat
loss requirements, making an insulation blanket unnecessary.
Should you choose to apply an insulation blanket to this
heater, you should follow these instructions. See the Features
and Components section of this manual for identication of
components mentioned below. Failure to follow these instructions
can restrict the air ow required for proper combustion, potentially
resulting in re, asphyxiation, serious personal injury or death.
• DO NOT apply insulation to the front of the combustion
chamber ange plate to insure that the spark igniter, ame
sensor, and sightglass remain uncovered.
• DO NOT cover the gas control valve or the Temperature-
Pressure Relief Valve.
• DO NOT apply insulation within 5” (13 cm) of the blower, to
insure the safe operation of the blower assembly.
• DO NOT apply insulation on the control box that encloses
the thermostat, ignition control, and variable frequency drive.
• DO NOT cover the instruction manual. Keep it on the side of
the water heater or nearby for future reference.
• DO obtain new warning and instruction labels from the
manufacturer for placement on the blanket directly over the
existing labels.
• DO inspect the insulation blanket frequently to make certain
it does not sag, thereby obstructing combustion air ow.
FIGURE 8.
The NSF Leg Kit (part number 9008883005) is needed only for
applications that must conform to NSF/ANSI Standard 5. The
installed height of the water heater will increase by 4" (10.2 cm)
when the leg kit is installed. Follow these steps to install the Leg Kit.
Use caution to prevent damage to the unit when installing the Leg Kit
1. Lift, tilt or lay the unit on its side to access the bottom of the legs.
2. Position the extension under leg aligning the holes in the leg
extension with the holes in the leg. Assemble the bolt, bevel
washers, at washers, and nut through the aligned holes in
the leg and leg extension as shown in Figure 8.
3. Once in place, tighten the nut and bolt assembly. Torque to 70
ft.lbs (9.67 kgf-m).
4. Insure that all four nut and bolt assemblies are torqued to the
specied value before placing the unit on the oor.
HARD WATER
Where hard water conditions exist, water softening or the
threshold type of water treatment is recommended. This will
protect the dishwashers, coffee urns, water heaters, water piping
and other equipment.
See the Maintenance Section in this manual for sediment and
lime scale removal procedures.
CIRCULATION PUMPS
A circulating pump is used when a system requires a circulating
loop or there is a storage tank used in conjunction with the water
heater. See Water Piping Diagrams in this manual for installation
location of circulating pumps.
See the Circulation Pump Wiring Diagrams (Figure 9.) in this
manual for electrical hookup information. Install in accordance
with the current edition of the National Electrical Code, NFPA 70
or the Canadian Electrical Code, CSA C22.1.
Stainless steel circulating pumps are recommended for use with
commercial water heaters.
10
Some circulating pumps are manufactured with sealed
CIRCULATING PUMP WIRING DIAGRAM
CIRCULATING PUMP WIRING DIAGRAM
DISHWASHER LOOP WITH TOGGLE SWITCH
FIELD SUPPLIED TEMPERATURE
CONTROL INSTALLED IN THE
CIRCULATING LOOP RETURN LINE
DISHWASHER
TOGGLE
SWITCH
CIRC
PUMP
MOTOR
L1 HOT
120 VAC
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 CONTROL SYSTEM
OPERATION.
CIRCULATING PUMP WIRING DIAGRAM
bearings and do not require further lubrication. Some
circulating pumps must be periodically oiled. Refer to
the pump manufacturer’s instructions for lubrication
requirements.
HIGH ALTITUDE INSTALLATIONS
Fire and Explosion Hazard
STORAGE TANK OR BUILDING RECIRCULATION
FIELD SUPPLIED TEMPERATURE CONTROL
INSTALLED IN THE STORAGE TANK
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 CONTROL SYSTEM
OPERATION.
L1 HOT
120 VAC
POWER
L2 NEUTRAL
OR CIRCULATING LOOP RETURN LINE
DISHWASHER LOOP WITH TOGGLE SWITCH
DISHWASHER
TOGGLE
SWITCH
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 CONTROL SYSTEM
OPERATION.
L1 HOT
120 VAC
POWER
L2 NEUTRAL
FIELD SUPPLIED TEMPERATURE
CONTROL INSTALLED IN THE
CIRCULATING LOOP RETURN LINE
FIGURE 9.
CIRC
PUMP
MOTOR
CIRC
PUMP
MOTOR
Under no circumstances should the
input exceed the rate shown on the
water heater’s rating label.
Overfiring could result in fire or
explosion.
Gas and carbon monoxide detectors are
available.
Breathing Hazard - Carbon Monoxide Gas
Under no circumstances should the input
exceed the rate shown on the water
heater’s rating label.
Special consideration must be taken with
installations above 10,100’ (3078m) for
standard models.
Overfiring could result in damage to the
water heater and sooting.
Gas and carbon monoxide detectors are
available.
Breathing carbon monoxide can cause brain damage or
death. Always read and understand instruction manual.
The water heaters covered by this manual are certied for use
without modication 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 orices. 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.
11
INSTALLATION REQUIREMENTS
GAS SUPPLY SYSTEMS
Low pressure building gas supply systems are dened 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
eld 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 specied 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 owing (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 red
appliances connected to the common main ring at full capacity.
If the supply pressure drops more than 1.5” W.C. (0.37 kPa)
as gas begins to ow 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 owing (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 specications.
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.
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.
Temperature 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
inrm 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 ts 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
satises 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 Qualied Installer or Service Agency. Follow mixing valve
manufacturer’s instructions for installation of the valves.
TABLE 5.
Water Temperature
(U.S. Government Memorandum, C.P.S.C., Peter L. Armstrong, Sept. 15, 1978)
12
°F (°C)
110 (43) (normal shower temp.)
116 (47) (pain threshold)
116 (47) 35 minutes 45 minutes
122 (50) 1 minute 5 minutes
131 (55) 5 seconds 25 seconds
140 (60) 2 seconds 5 seconds
149 (65) 1 second 2 seconds
154 (68) instantaneous 1 second
Time for 1st Degree Burn
(Less Severe Burns)
Time for Permanent Burns
2nd & 3rd Degree
(Most Severe Burns)
HOT WATER
OUTLET
TEMPERED WATER
OUTLET
12” TO 15”
(30-38 cm)
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
COLD
WATER
INLET
CHECK
VALV E
TO TANK
INLET
CHECK
VALV E
MIXING
VALV E
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 ow by throttling a full port ball valve installed in the
circulating line on the outlet side of the pump. Never throttle ow
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 ow 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
Explosion Hazard
Temperature-Pressure Relief Valve
must comply with ANSI Z21.22CSA 4.4 and ASME code.
Properly sized temperaturepressure 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
certied combination Temperature-Pressure Relief Valve (T&P
valve) by the manufacturer. The valve is certied 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 TemperaturePressure Relief Valve rated/sized and certied 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 TemperaturePressure 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 tting 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 oor 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.
13
No valve or other obstruction is to be placed between the
CAUTION
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 ow may cause property damage.
Water Damage Hazard
Temperature-Pressure Relief Valve discharge
•
pipe must terminate at adequate drain.
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 oor
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.
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 Hazard
Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this or any other appliance.
Avoid all ignition sources if you smell gas.
Do not expose water heater controls to excessive gas
pressure.
Use only the gas shown on the water heater rating label.
Maintain required clearances to combustibles.
Keep ignition sources away from faucets after extended
periods of non-use.
Read instruction manual before
installing, using or servicing
water heater.
Keep water heater area clear and free of combustible materials,
gasoline and other ammable vapors and liquids.
CONTAMINATED AIR
Burn hazard.
Hot water discharge.
Keep clear of TemperaturePressure Relief Valve
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,
Breathing Hazard - Carbon Monoxide Gas
Install water heater in accordance with
the Instruction Manual and NFPA 54 or
CAN/CSA-B149.1.
To avoid injury, 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 ue 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).
14
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 injury, 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 insufcient 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
ame, causing sooting of the combustion chamber, burners and
ue tubes and creates a risk of asphyxiation.
Do not install the water heater in a conned space unless an
adequate supply of air for combustion and ventilation is brought
in to that space using the methods described in the Conned
Space section that follows.
Never obstruct the ow 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 re or explosion
and cause property damage, serious bodily injury or death.
UNCONFINED SPACE
An Unconned 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 unconned space.
Makeup air requirements for the operation of exhaust fans,
kitchen ventilation systems, clothes dryers and replaces shall
also be considered in determining the adequacy of a space to
provide combustion, ventilation and dilution air.
Unusually Tight Construction
In unconned spaces in buildings, inltration may be adequate
to provide air for combustion, ventilation and dilution of ue
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 Conned Space section that follows.
CONFINED SPACE
A Conned 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 conned spaces. The required size for
the openings is dependent on the method used to provide fresh
air to the conned 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, sufcient 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 re
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 specied. 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 xed in the open position.
15
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 conned spaces. The
illustrations shown in this section of the manual are a reference
for the openings that provide fresh air into conned 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
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 14.
The conned 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 16.
The conned 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).
FIGURE 15.
16
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