A.O. Smith HWH-120, HWH-160, HWH-200, HWH-225 Installation Manual
GAS FIRED COMMERCIAL WATER HEATERS
25589, Highway 1
McBee, SC 29101
WARNING: If the information in these
instructions is not followed exactly, a fire
or explosion may result causing property
damage, personal injury or death.
Instruction Manual
MODELS: HWH
120, 160, 200, 225
SERIES 100, 101
INSTALLATION - OPERATION
MAINTENANCE - LIMITED WARRANTY
INDOOR ONLY
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.
PRINTED 1215 327947-001
TABLE OF CONTENTS
SAFE INSTALLATION, USE AND SERVICE.........................................3
GENERAL SAFETY...............................................................................4
Grounding Instructions ......................................................................4
Correct Gas ....................................................................................... 4
Precautions .......................................................................................4
Propane or Liqueed Petroleum (LP) Gas Models ............................ 4
High Altitude Installations .................................................................. 4
Field Installed Components ...............................................................4
Abbreviations Used ...........................................................................5
Qualied Installer or Service Agency .................................................5
Preparing for the Installation .............................................................5
INTRODUCTION ................................................................................... 5
DIMENSIONS AND CAPACITY DATA ................................................... 6
CONTROL COMPONENTS .................................................................. 7
Automatic Reset Limit Control ...........................................................8
Ignition Control ..................................................................................8
Thermal Balancer .............................................................................. 8
Manual Reset High Limit Switch ........................................................ 8
Tank Temperature Control (not supplied) ..........................................9
Thermometers (not supplied) ............................................................9
Drain Valve (not supplied) ................................................................. 9
Circulation Pumps (not supplied) ......................................................9
Flow switch (not supplied) ................................................................. 9
INSTALLATION CONSIDERATIONS .................................................. 11
General ............................................................................................ 11
Hard Water ...................................................................................... 11
Water Piping Diagrams .................................................................... 11
Internal Contaminants .....................................................................11
INSTALLATION REQUIREMENTS ..................................................... 12
Location ...........................................................................................12
Mixing Valves ...................................................................................12
Dishwashing Machines .................................................................... 13
Closed Water Systems ....................................................................13
Thermal Expansion .........................................................................13
Gas supply Systems ........................................................................ 13
Supply Gas Regulator .....................................................................13
Pressure Relief Valve ......................................................................13
Combustible Material Storage ......................................................... 14
Contaminated Air ............................................................................. 14
Installation Clearances .................................................................... 15
Leveling ........................................................................................... 15
System Connections .......................................................................15
Air Requirements ............................................................................. 15
Unconned Space ........................................................................... 15
Unusually Tight Construction ...........................................................15
Conned Space ...............................................................................15
Direct Vent Water Heaters ...............................................................15
Exhaust Fans ..................................................................................15
Louvers and Grilles .........................................................................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 ......................................... 16
Air From Other Indoor Spaces ........................................................17
Gas Connections .............................................................................17
VENTING .............................................................................................19
Standard Venting ............................................................................. 19
Venting System ...............................................................................20
GAS SUPPLY CONNECTIONS ..........................................................22
Gas Supply Pipe Connections ......................................................... 22
Gas Pressure Requirements ........................................................... 22
Pipe Sizes for Propane Gas ............................................................ 22
Purging Gas Line ............................................................................. 22
Check Gas Supply Inlet Pressure ...................................................22
Check for Gas Leaks .......................................................................22
WATER HEATER START UP AND OPERATIONS .............................. 24
Precautions .....................................................................................24
Checking and Adjusting Input .......................................................... 25
SEQUENCE OF OPERATION FLOWCHART ..................................... 26
OPERATING INSTRUCTIONS ............................................................27
TROUBLESHOOTING ........................................................................28
LED Status and Troubleshooting .....................................................33
Flame Current Measurement ..........................................................35
GENERAL MAINTENANCE ................................................................ 36
Manual Reset High Limit Switch Continuity Test .............................36
Pressure Relief Valve Test ............................................................... 36
Pilot and Main Burner ......................................................................36
Thermal Balancer (HWH-200, HWH-225) ....................................... 38
Venting Maintenance ....................................................................... 38
Lime Scale Removal .......................................................................38
Circulating Pump ............................................................................. 38
WIRING ............................................................................................... 39
Wiring Connections .........................................................................39
PIPING DIAGRAMS ............................................................................ 44
NOTES ................................................................................................ 46
LIMITED WARRANTY ......................................................................... 47
2
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.
symbol indicates a potentially hazardous
situation which, if not avoided, could result in
property damage.
APPROVALS
3
GENERAL SAFETY
GROUNDING INSTRUCTIONS
This water heater must be grounded in accordance with the
National Electrical Code, Canadian Electrical Code and/or local
codes. This water heater is polarity sensitive; correct wiring is
imperative for proper operation.
This water heater must be connected to a grounded metal,
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.
CORRECT GAS
Make sure the gas on which the water heater will operate is the
same as that speci ed on the water heater rating plate. Do not
install the water heater if equipped for a different type of gas;
con sult your supplier.
PRECAUTIONS
If the unit is exposed to the following, do not operate until all
corrective steps have been made by a qualied service technician:
1. Exposure to re.
2. If damaged.
3. Firing without water.
4. Sooting.
If the water heater has been exposed to ooding, it must be
replaced.
PROPANE OR LIQUEFIED PETROLEUM (LP) GAS MODELS
Water heaters for propane (LP) gas are different from natural
gas models. A natural gas water heater will not function safely on
propane (LP) gas and no attempt should be made to convert a
water heater from natural gas to propane (LP) gas.
Propane (LP) gas must be used with great caution. It is highly
explosive and heavier than air. It collects rst in the low areas
making its odor difcult to detect at nose level. If propane (LP)
gas is present or even suspected, do not attempt to nd the cause
yourself. Leave the building, leaving doors open to ventilate, then
call your gas supplier or service agent. Keep area clear until a
service call has been made.
At times you may not be able to smell an propane (LP) gas
leak. One cause is odor fade, which is a loss of the chemical
odorant that gives propane (LP) gas its distinctive smell. Another
cause can be your physical condition, such as having a cold or
diminishing sense of smell with age. For these reasons, the use
of a propane gas detector is recommended.
If you experience an out of gas situation, do not try to relight
water heaters yourself. Call your local service agent. Only
trained propane (LP) professionals should conduct the
required safety checks in accordance with industry standards.
HIGH ALTITUDE INSTALLATIONS
Verify that the elevation of the installation is within the altitude
range stamped on the rating plate of the appliance.
U.S. Requirements
If the altitude range stamped on the appliance nameplate does
not match the installation elevation, contact Technical Support
at 1-800-527-1953 for guidance.
Canadian Requirements
If the altitude range stamped on the appliance nameplate does
not match the installed elevation, contact the gas supplier for
guidance.
FIELD INSTALLED COMPONENTS
When installing the water heater, the follow ing compo nents must
be installed:
• Circulating Pump
• Storage Tank Temperature Control
• Storage Tank (Temperature & Pressure Relief Valve)
• Thermometers
• Flow Switch
• Drain Valve
4
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
• NEC - National Electrical Code
• NFPA - National Fire Protection Association
• UL - Underwriters Laboratory
• CSA - Canadian Standards Association
• AHRI - Air Conditioning, Heating and Refrigeration Institute
QUALIFIED INSTALLER OR SERVICE AGENCY
Installation and service of this water heater requires ability
equivalent to that of a Qualified Agency (as defined by
ANSI below) in the field 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 2006 Sec. 3.3.83: “Qualied Agency” - “Any
individual, rm, corporation or company that either in person or
through a representative is engaged in and is responsible for (a)
the installation, testing or replacement of gas piping or (b) 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 entire manual before attempting to install or
operate the water heater. Pay close attention to the General
Safety Information on page 4. If you don’t follow the safety
rules, the water heater may not operate safely. It could
cause property damage, injury and/or death.
This manual contains instructions for the installation,
operation, and maintenance of the 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.
Detailed installation diagrams are also found in this manual.
These diagrams will serve to provide the installer with a
reference. It is essential that all venting, water piping, gas
piping and wiring be installed as shown.
Particular attention should be given to the installation
of thermometers at the locations indicated in the piping
diagrams as these are necessary for checking the operation
of the water heater.
The principal components of the water heater are identied
in Control Components on pages 7, 8, 9 and 10 in this
manual. Use this reference to locate and identify various
components on the water heater.
See Troubleshooting on page 28. By using this information
the user may be able to make minor operational adjustments
and avoid unnecessary service calls. However, service
and diagnostic procedures should only be performed by a
Qualied Service Agency.
Note: Costs to correct installation errors are not covered
under the limited warranty.
2. Be sure to turn off power when working on or near the
electrical system of the water heater. Never touch electrical
components with wet hands or when standing in water.
3. The installation must conform to all instructions contained in
this manual and the local code authority having jurisdiction.
These shall be carefully followed in all cases. Authorities
having jurisdiction should be consulted before installation
begins if there are any questions regarding compliance with
local, state or national codes.
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 National Electrical Code,
NFPA 70 or CAN/CSA-B149.1, the Natural Gas and Propane
Installation Code and CSA C22.1, the Canadian Electrical
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.
4. If after reading this manual you have any questions or do
not understand any portion of the instructions, call the toll
free number on the back cover of this manual for technical
assistance. In order to expedite your request, please have
the full Model, Serial and Series number of the water heater
you are working with available for the technician. This
information is located on the water heater’s rating label.
5. Carefully plan the placement of the water heater. Examine
the location to ensure that it complies with the requirements
in Location on page 12.
6. For installation in California this water heater must be braced or
anchored 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,
1102 Q Street, Suite 5100, Sacramento, CA 95811.
5
DIMENSIONS AND CAPACITY DATA
TABLE 1. ROUGH-IN DIMENSIONS
Models
Dimensions
A 49 3/8 1254 50 1/8 1273 53 1/4 1353 60 1524
B 30 3/8 772 30 3/8 772 33 1/8 841 33 1/8 841
C 23 5/8 600 23 5/8 600 27 1/8 689 27 1/8 689
D 20 3/4 527 20 3/4 527 20 3/4 527 20 3/4 527
E 5 1/2 140 5 1/2 140 5 1/2 140 5 1/2 140
F 10 254 10 254 10 254 10 254
G 11 13/16 300 11 13/16 300 11 13/16 300 11 13/16 300
H 6 152 7 178 7 178 7 178
J 26 11/16 678 26 11/16 678 26 11/16 678 26 11/16 678
K 20 3/4 527 20 3/4 527 20 3/4 527 20 3/4 527
L 1 1/4 NPT 1 1/4 NPT 1 1/4 NPT 1 1/4 NPT
M 1 NPT 1 NPT 1 NPT 1 NPT
N 1/2 NPT 1/2 NPT 1/2 NPT 1/2 NPT
W 1 3/4 44 1 3/4 44 1 3/4 44 1 3/4 44
Approx.
Shipping
Weight
HWH-120 HWH-160 HWH-200 HWH-225
Inches mm Inches mm Inches mm Inches mm
120 lbs. 54 Kg. 155 lbs. 70 Kg. 165 Lbs. 75 Kg. 175 lbs. 79 Kg.
FIGURE 1. DIMENSIONS
TABLE 2. RECOVERY CAPACITIES
Model
HWH 120 120000 35
HWH 160 160000 47
HWH 200 199000 58
HWH 225 225000 66
NOTE: A temperature rise of 30°F is recommended for all models.
Input
BTUH KW T ° C 11 17 22 28 33 39
T ° F 20 30 40 50 60 70
GPH 576 385 288 230 192 164
LPH 2179 1457 1090 872 726 623
GPH 767 513 384 307 256 219
LPH 2905 1943 1453 1162 968 830
GPH 954 638 477 382 318 273
LPH 3614 2417 1807 1445 1205 1032
GPH 1079 722 540 432 360 308
LPH 4086 2732 2043 1634 1362 1167
U.S. Gallons/Hr and Litres/Hr. at TEMPERATURE RISE INDICATED
ELECTRICAL REQUIREMENTS
TABLE 3. ELECTRICAL REQUIREMENTS: HWH-120 THROUGH 225
Models Supply Voltage (Volts) Frequency (Hz) Current (AMPS)
All 120 60 <5
GAS REQUIREMENTS
TABLE 4. GAS REQUIREMENTS: HWH-120 THROUGH 225
Models
All - Natural Gas 4.5 1.1 13.0 3.2 3.5 0.87
All - Propane 10 2.5 13.5 3.4 10 2.5
Minimum Inlet Gas Pressure Maximum Inlet Gas Pressure Manifold Pressure
in. W.C. kPa in. W.C. kPa in. W.C. kPa
6
CONTROL COMPONENTS
FIGURE 2. COMPONENT LOCATIONS
7
AUTOMATIC RESET LIMIT CONTROL
FIGURE 3. AUTO RESET LIMIT CONTROL
The automatic reset limit control, Figure 3, is an automatic safety
device that activates at a water temperature of approximately 195°F
(91°C). This limits the water outlet temperature to a maximum of
200°F (93°C).
The device is wired in series with the gas valve. The control will
automatically reset when the outlet water temperature decreases to
approximately 190°F (88°C).
Should the automatic reset limit control activate during a heating
cycle, the water heater’s gas valve will close; extinguishing the main
burners. The pilot burner will also be extinguished. The circulating
pump will continue operating as long as the storage tank thermostat
continues to “call for heat”. When the outlet water temperature
from the water heater drops to 190°F (88°C) or below, the control
module will begin an ignition cycle that will relight the pilot burner
and main burners if the storage tank thermostat continues to call
for heat. Otherwise, the normal operating cycle will resume on the
thermostat’s next call for heat.
IGNITION CONTROL
The Honeywell S-8600 ignition control contains the electronic
components of the system and also serves as a control wiring
system for the controls mounted on the water heater. The ignition
control performs the following functions:
1. Checks for safe-start by sensing for a false ame condition
on start-up.
2. Generates a potential of 15,000 volts for spark ignition of the
pilot burner.
3. Opens the pilot valve.
4. Discontinues ignition spark when the pilot ame is
established. The S-8600 control used on propane gas
models provides safety lockout if the pilot fails to ignite within
the pilot ame establishing period. The S-8600 control used
on natural gas models continues trial for ignition until pilot
ame is established.
5. After proof of pilot ame, opens the main valve.
6. On a power loss, shuts the water heater down. When power is
restored it will begin a new ignition cycle.
7. On a loss of ame, shuts off main gas and starts trial for pilot ignition.
Please refer to TROUBLESHOOTING SECTION for more
information.
FIGURE 4. IGNITION CONTROL
THERMAL BALANCER
The thermal balancer (standard on Models HWH-200 and
HWH-225) is a delay relay used to control the pump on the
water circulation system. The thermal balancer provides an
immediate start for the pump but delays the shutoff of the pump
for approximately 2 minutes after the burner has turned off. The
extra pump operating time helps to recover residual heat from
the heat exchanger to improve the efciency of the appliance
and also to balance the heat exchanger temperature with the
tank temperature after shutdown.
MANUAL RESET HIGH LIMIT SWITCH
This water heater is equipped with a manual reset high limit
switch, located under the small cover on the side of the jacket,
see Figure 5. This device provides positive shutdown of the
water heater in the event of water heater or system malfunction.
Should the temperature of the copper tube reach 210°F (99°C),
the high limit switch will activate, the gas control valve will close,
the pilot and main burners will be extinguished. If the high limit
switch should shut off unit, check the following conditions:
• No water in water heater.
• Restricted water ow through the water heater.
• Improper wiring (water heater ring without circulating
pump operating).
• Pump failure.
After correcting failure condition remove the switch cover and
push the reset button. The high limit switch may be reset after
the coil surface decreases to 204°F (96°C).
FIGURE 5. MANUAL RESET HIGH LIMIT SWITCH
8
CIRCULATING PUMP WIRING DIAGRAM
CIRCULATING PUMP WIRING DIAGRAM
TANK TEMPERATURE CONTROL (NOT SUPPLIED)
The water temperature in the storage tank is controlled by the
Tank Temperature Control. The sensing element is mounted
inside the hot water storage tank.
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.
The tank temperature control is adjustable from 100°F (38°C)to
190°F (88°C). It is recommended that lower water temperatures
be used to avoid the risk of scalding. It is further recommended,
in all cases, that the water temperature be set for the lowest
temperature which satises the user’s hot water needs. This
will also provide the most energy efcient operation of the water
heater and minimize scale formation.
The water heater should be located in an area where the general
public does not have access to set temperatures. Setting the
water temperature at 120°F (49°C) will reduce the risk of scalds.
A change in water temperature in the storage tank lower than the
Tank Temperature Control setting will cause the sensor to close
its contacts and consequently energize the water heater.
If the Tank Temperature Control is out of calibration, replace it
with a new one; do not attempt to x this control.
THERMOMETERS (NOT SUPPLIED)
Thermometers should be obtained and eld installed as shown in
the installation diagrams.
Thermometers are installed in the system as a means of detecting a
possible liming condition in the water heater. Record the temperature
rise at initial start-up for future reference. A temperature rise of 30°F
(17°C) is recommended for all models at initial start-up. An increase
of 5°F (3°C) over the recorded temperature rise through the water
heater is an indication that lime is present. The term "temperature rise"
designates the difference between the water heater inlet and outlet
water temperature.
DRAIN VALVE (NOT SUPPLIED)
A drain valve must be obtained and installed on each water
heater and tank for draining purposes.
CIRCULATION PUMPS (NOT SUPPLIED)
A circulating pump is used to circulate water between the
storage tank and the water heater. See Water Piping Diagrams
in this manual for installation location of circulating pumps.
See the Circulation Pump Wiring Diagrams in this manual
for electrical hookup information. Install in accordance with
the current edition of the National Electrical Code, NFPA 70
or the Canadian Electrical Code, CSA C22.1.
Constant circulating pump operation of the water heater voids
the warranty. Constant water ow through the unit will “wash”
away the copper’s natural protective coating. This is called
velocity erosion. This erosion is not as great a problem when
intermittent circulating operation is used per the recommended
installation procedure. Constant circulation of water through
the building’s system main is permissible as long as the water
does not constantly ow through the water heater.
Stainless steel circulating pumps are recommended for use
with commercial water heaters.
Some circulating pumps are manufactured with sealed bearings
and do not require further lubrication. Some circulating pumps
must be periodically oiled. Refer to the pump manufacturer’s
instructions for lubrication requirements.
STORAGE TANK OR BUILDING RECIRCULATION
TEMPERATURE CONTROL INSTALLED
IN THE STORAGE TANK OR CIRCULATING
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
LOOP RETURN LINE
CIRC
PUMP
MOTOR
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
TEMPERATURE CONTROL INSTALLED IN
THE CIRCULATING LOOP RETURN LINE
CIRC
PUMP
MOTOR
FIGURE 6. CIRCULATING PUMP WIRING DIAGRAMS
FLOW SWITCH (NOT SUPPLIED)
The ow switch is a safety device which must be installed at the
water outlet of the unit to prevent main burner operation in the
event of inadequate water ow through the unit.
An accessory package containing a ow switch is available for
this application.
This switch may be mounted in a horizontal pipe line or a vertical
pipe line with upward water ow. Do not install the switch where
the water ow is downward.
For proper performance mount the switch in a section of pipe
where there is a straight run of at least 5 pipe diameters on each
side of the ow switch (i.e. do not locate adjacent to valves,
elbows, orices, etc.).
The ow switch shall be mounted in a standard 1" x 1" x 1" tee for
the 120, 160 and 200 models. The 225 model should be installed
with a 1 1/4" x 1 1/4" x 1" reducing tee. Install the ow switch in
the branch (top) opening of the reducing tee and provide adequate
paddle length in the ow stream. The paddle must be adjusted
or trimmed to the size of the pipe in which it will be installed, see
Figure 7.
9
Any part of the paddle must not touch the pipe or any restrictions
in the pipe. Screw the ow switch in position so the at of the
paddle is at right angles to the ow. The arrow on the side case
must point in the direction of the ow.
TABLE 5. FLOW SWITCH
Minimum Flow Rate
Contacts Closed
Model Number
HWH-120 through 225 4.5 17.0 3.5 13.2
(Flow)
GPM LPM GPM LPM
Contacts Open
(No Flow)
The ow switch may be eld adjusted to obtain higher minimum
ow rates than those shown in Table 5.
To adjust the ow rate setting:
1. Remove the ow switch cover.
2. For higher ow rate - turn the range adjusting screw
clockwise.
3. For lower ow rate-turn the range adjusting screw
counterclockwise.
The switch is factory set at approximately the minimum ow rate,
refer to Table 5. It must not be set lower than the factory setting
as this may result in the switch failing to return at a 'no ow'
condition.
4. Replace ow switch cover.
Where units are installed in multiples, each water heater must
be individually protected by a ow switch.
FIGURE 7. FLOW SWITCH
10
INSTALLATION CONSIDERATIONS
GENERAL
If the system is to be lled with water for testing or other purposes
during cold weather and before actual operation, care must be
taken to prevent freezing of water in the system. Failure to do
so may cause the water in the system to freeze with resulting
damage to the system. Damage due to freezing is not covered
by the warranty.
Before locating the water heater:
1. Check for nearby connection to:
• System water piping
• Venting connections
• Gas supply piping
• Electrical power
2. Locate the water heater so that if water connections should
leak, water damage will not occur. When such locations
cannot be avoided, it is recommended that a suitable drain
pan, adequately drained, be installed under the appliance.
The pan must not restrict combustion air ow. Under no
circumstances is the manufacturer to be held responsible
for water damage in connection with this appliance, or any
of its components.
3. Check area around the water heater. Remove any
combustible materials, gasoline and other ammable liquids.
4. Make sure the gas control system components are protected
from dripping or spraying water or rain during operation or service.
HARD WATER
Where hard water conditions exist, water softening or the
threshold type of water treatment is recommended. This will
protect dishwashers, coffee urns, water heaters, water piping
and other equipment. See the General Maintenance section in
this manual for information concerning lime scale removal.
WATER PIPING DIAGRAMS
This manual provides detailed water piping diagrams for typical
methods of application for the water heaters, see Water Piping
Diagrams beginning on page 44.
The water heater must be installed with a separate storage tank.
A pump provides water circulation between the storage tank and
the water heater. 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 the Water
Piping Diagrams beginning on page 44.
INTERNAL CONTAMINANTS
The system must be internally cleaned and ushed after a new
or replacement water heater has been installed, to remove
contaminants that may have accumulated during installation.
Failure to ush contaminants from a system can cause solids
to form on the inside of heat exchangers, create excessive
blockage of water circulation, and deteriorate pump seals and
impellers.
11
INSTALLATION REQUIREMENTS
WA
LOCATION
When installing the water heater, consideration must be given to
proper location. The location selected should provide ade quate air
supply and be as centralized with the piping system as possible.
The location must be as close as practicable to a chimney or
gas vent. This location should also be such that the gas ignition
system components are protected from water dripping, spraying,
etc.) during water heater operation and service (circulating pump
replacement, control replacement, etc.).
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 6. 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 8.) 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 6.
Water Temperature °F
110 (normal shower temp.)
116 (pain threshold)
116 35 minutes 45 minutes
122 1 minute 5 minutes
131 5 seconds 25 seconds
140 2 seconds 5 seconds
149 1 second 2 seconds
154 instantaneous 1 second
(U.S. Government Memorandum, C.P.S.C., Peter L. Armstrong, Sept. 15,1978)
Time for 1st Degree Burn
(Less Severe Burns)
Time for Permanent Burns
2nd & 3rd Degree
(Most Severe Burns)
HOT WATER
OUTLET
12” TO 15”
(30-38 cm)
TEMPERED WATER
OUTLET
TO TANK
INLET
MIXING
VALV E
CHECK
VALV E
Some local codes permit operation of gas appliances if installed
18 inches (45.7 cm) or more above the oor. This may reduce the
risk if location in such an area cannot be avoided.
COLD
TER
INLET
CHECK
VALV E
This water heater is intended for indoor installation only and should
not be installed where freezing temperatures or any moisture
could damage the external components of the water heater.
FIGURE 8.
12
DISHWASHING MACHINES
All dishwashing machines meeting the National Sanitation
Foundation requirements are designed to operate with water ow
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 ow 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 ow rate 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 expand when it is heated. As the
volume of water expands there will be a corresponding increase
in water pressure due to thermal expansion. Thermal expansion
can cause premature tank failure (leakage). This type of failure
is not covered under the limited warranty. Thermal expansion
can also cause intermittent Temperature-Pressure Relief Valve
operation: water discharged from the valve due to excessive
pressure build up. This condition is not covered under the limited
warranty. The Temperature-Pressure Relief Valve is not intended
for the constant relief of thermal expansion.
A properly sized thermal expansion tank must be installed on
all closed systems to control the harmful effects of thermal
expansion. Contact a local plumbing service agency to have a
thermal expansion tank installed.
GAS SUPPLY SYSTEMS
Low pressure building gas supply systems are defined as
those systems that cannot under any circumstances exceed
14" W.C. (3.5 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. (3.5 kPa) (1/2 PSI Gauge). These systems
must use eld supplied regulators to lower the gas pressure to
less than 14" W.C. (3.5 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 (34.5 kPa) building pressure should be designed
by gas delivery professionals for best performance. Water
heaters connected to gas supply systems that exceed 14" W.C.
(3.5 kPa) (1/2 PSI Gauge) at any time must be equipped with a
gas supply regulator.
All models require a minimum gas supply pressure of 4.5" W.C.
(1.1 kPa) for Natural Gas and 10" W.C. (2.5 kPa) for Propane.
The minimum supply pressure is measured while gas is owing
(dynamic pressure). The supply pressure should never fall
below 4.5" W.C. (1.1 kPa) for Natural Gas and 10" W.C. (2.5
kPa) for Propane. 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 valve on all models has a maximum gas supply pressure
limit of 14" W.C. (3.5 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 13" W.C. (3.2 kPa) for Natural gas and 13.5" W.C.
(3.4kPa) for Propane gas. Install a positive lock-up gas pressure
regulator in the gas supply line if inlet gas pressure can exceed
these maximum allowable pressures 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. Positive lock-up gas pressure regulator(s) should be installed
no closer than 3 equivalent feet (1 meter) and no farther than
8 equivalent feet (2.4 meters) from the water heater’s inlet
gas connection.
3. After installing the positive lock-up gas pressure regulator(s)
an initial nominal supply pressure setting of 7.0” W.C. (1.7
kPa) for Natural Gas and 12" W.C. (3.0 kPa) for Propane
while the water heater is operating is recommended and
will generally provide good water heater operation. Some
additional adjustment maybe required later to maintain a
steady gas supply pressure.
4. When installing multiple water heaters in the same gas supply
system it is recommended that individual positive lock-up gas
pressure regulators be installed at each unit.
PRESSURE RELIEF VALVE
An ASME rated pressure relief valve is furnished with the water
heater. The pressure relief valve is to be installed in the hot water
outlet line as near to the water heater as possible. Never operate
the gas burner without being certain the water heater is lled with
water and a properly sized pressure relief valve is installed.
The pressure rating of the relief valve should be equal to or less
than the rated pressure capacity of any component in the system
including the water heater. Should the valve need to be replaced,
call the toll free phone number listed on the back of this manual
for further technical assistance.
13
Explosion Hazard
CAUTION
Relief Valve must comply with
ASME code.
Properly sized Relief Valve must
be installed.
Can result in overheating and
excessive tank pressure.
Can cause serious injury or death.
A discharge pipe from the relief valve should terminate at an
adequate oor drain. Do not thread, plug, or cap the end of the
drain line.
Water Damage Hazard
Pressure Relief Valve discharge pipe must
•
terminate at adequate drain.
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 appliance area clear and free of combustible materials,
gasoline and other ammable vapors and liquids.
CONTAMINATED AIR
The Discharge Pipe:
• 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 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.
Once the water heater is installed and lled with water and
the system is pressurized, manually test the operation of the
pressure relief valve. See the maintenance section of this manual
for instructions.
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 heat exchanger 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
INSTALLATION CLEARANCES
These water heaters are approved for installation on combustible
ooring in an alcove with minimum clearance to combustibles or
noncombustibles shown in Table 7.
TABLE 7. INSTALLATION CLEARANCES
All Models
TOP 44" (112 cm)
SIDES 6" (15 cm)
REAR 6" (15 cm)
VENT 6" (15 cm)
2 inches (51 mm) clearance is allowable from combustible
construction for hot water pipes.
When the appliance is installed directly on carpeting, the appliance
shall be installed on a metal or wood panel extending beyond the full
width and depth of the appliance by at least 3 inches (76.2 mm) in
any direction. If the appliance 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 water heater when full of water.
Sufcient area should be provided at the front and rear of the unit
for proper servicing. Clearances of 24 inches (61 cm) in the rear
and 48 inches (122 cm) in the front are required by code. In a utility
room installation, the door shall be wide enough to allow the water
heater to enter or to permit the replacement of another appliance
such as a water heater.
LEVELING
Each unit should be checked after installation to be certain that it
is level prior to starting the unit.
If the unit is not level, obtain and insert shims under the base ring
of the unit to correct this condition.
SYSTEM CONNECTIONS
The system installation must conform to these instructions and to
the requirements of the local code authority having jurisdiction.
Good practice requires that all heavy piping be supported.
AIR REQUIREMENTS
Breathing Hazard - Carbon Monoxide Gas
Install appliance 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 the 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.
DIRECT VENT WATER HEATERS
Water heaters installed in a direct vent conguration that derive
all air for combustion from the outdoor atmosphere through
sealed intake air piping are not factored in the total water heater
input Btu/hr calculations used to determine the size of openings
providing fresh air into conned spaces.
EXHAUST FANS
Where exhaust fans are installed, additional air shall be provided
to replace the exhausted air. When an exhaust fan is installed
in the same space with a water heater, 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
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