A.O. Smith LTE 66D, LTE 80D, LTE 120D Installation Manual

Instruction Manual

COMMERCIAL ELECTRIC WATER HEATERS

MODELS LTE 66D, LTE 80D & LTE 120D, Series 200

INSTALLATION - OPERATION - SERVICE

- MAINTENANCE - LIMITED WARRANTY

500 Tennessee Waltz Parkway

Ashland City, TN 37015

®

Thank you for buying this energy efcient water heater.
We appreciate your condence in our products.

PLACE THESE INSTRUCTIONS ADJACENT TO HEATER AND NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.

PRINTED 0316 100270491

1

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 hazardous

DANGER

WARNING

CAUTION

situation which, if not avoided, will result in
death or injury.

WARNING indicates a potentially hazardous
situation which, if not avoided, could result
in death or injury.

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.

IMPORTANT DEFINITIONS

•  QualiedInstallerorServiceAgency:

Installation and service of this water heater requires ability equivalent to that of a Qualied Agency (as dened by ANSI below) in the

eld involved. Installation skills such as plumbing, electrical supply are required in addition to electrical testing skills when performing
service.

•  ANSIZ223.12006Sec.3.3.83:

“Qualied 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.”

2

GENERAL SAFETY INFORMATION

Improper installation, use and service may

result in property damage.

CAUTION

• Do not operate water heater if any part has been

exposed to flooding or water damage.

•

Inspect anode rods regularly, replace when significantly depleted.

• 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.

PRECAUTIONS

DO NOT USE THIS WATER HEATER IF ANY PART HAS BEEN
EXPOSED TO FLOODING OR WATER DAMAGE. Immediately
call a qualied service technician to inspect the water heater and to
replace any part of the control system which has been under water.

If the unit is exposed to the following, do not operate heater until all
corrective steps have been made by a qualied 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. Failure to ground this water heater properly
may also cause erratic control system operation on ELECTRONIC
CONTROL models.

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.

When servicing this unit, verify the power to the unit is turned off prior to opening the control cabinet door.

HYDROGEN GAS (FLAMMABLE)

Hydrogen gas can be produced in a hot water system served by this
heater that has not been used for a long period of time (generally two
weeks or more). Hydrogen gas is extremely ammable.
risk of injury under these conditions, it is recommended that the hot water
faucet be opened for several minutes at the kitchen sink before using any
electrical appliance connected to the hot water system. If hydrogen is present
there will probably be an unusual sound such as air escaping through the
pipe as the water begins to ow.
OR OPEN FLAME NEAR THE FAUCET AT THE TIME IT IS OPEN.

THERE SHOULD BE NO SMOKING

To reduce the

3

TABLE OF CONTENTS

SAFE INSTALLATION, USE, AND SERVICE....................................... 2

GENERAL SAFETY INFORMATION .................................................... 3

Precautions .................................................................................. 3

Hydrogen Gas (Flammable) ......................................................... 3

INTRODUCTION .................................................................................. 4

Preparing for the Installation ........................................................ 4

DIMENSIONS AND CAPACITIES DATA .............................................. 5

APPROVALS ........................................................................................ 6

MODEL AND RATING .......................................................................... 6

FEATURES AND COMPONENTS ....................................................... 7

LOCATING THE NEW WATER HEATER ............................................. 8

Facts to Consider About the Location .......................................... 8

Clearances ................................................................................... 8

INSTALLATION .................................................................................... 9

Required Ability ............................................................................ 9

General ......................................................................................... 9

Contaminated Water ..................................................................... 9

Circulating Pump .......................................................................... 9

Insulation Blankets ....................................................................... 9

Temperature-Pressure Relief Valve .............................................. 9

Closed Water Systems ............................................................... 10

Thermal Expansion .................................................................... 10

INTRODUCTION

ELECTRICAL ......................................................................................11

General ........................................................................................11

Branch Circuit ..............................................................................11

Calculating Amperage/Overcurrent Protection ............................11

WIRING DIAGRAMS .......................................................................... 12

OPERATION ....................................................................................... 13

General ....................................................................................... 13

Filling the Water Heater .............................................................. 13

Initial Start Up ............................................................................. 13

Draining the Water Heater .......................................................... 13

TEMPERATURE REGULATION ........................................................ 14

Temperature Adjustment ............................................................ 14

MAINTENANCE ................................................................................. 15

General ....................................................................................... 15

Anode Rod Inspection ................................................................ 15

TROUBLESHOOTING CHECKLIST .................................................. 16

Checklist ..................................................................................... 16

Leakage Checkpoints ................................................................. 17

WARRANTY ....................................................................................... 18

Repair Parts List ......................................................................... 19

NOTES ............................................................................................... 21

Thank You for purchasing this water heater. Properly installed
and maintained, it should give you years of trouble free service.

Abbreviations Found In This Instruction Manual:

• ANSI - American National Standards Institute

• AHRI - Air-Conditioning, Heating and Refrigeration Institute

• NEC - National Electrical Code

• NFPA - National Fire Protection Association

• UL - Underwriters Laboratory

PREPARING FOR THE INSTALLATION

1. Read the “General Safety Information” section of this manual

rst and then the entire manual carefully. If you don’t follow
the safety rules, the water heater may not operate safely. It
could cause DEATH, SERIOUS BODILY INJURY AND/OR
PROPERTY DAMAGE.

This manual contains instructions for the installation, operation,

and maintenance of the electric 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. READ

THE ENTIRE MANUAL BEFORE ATTEMPTING TO INSTALL
OR OPERATE THE WATER HEATER.

Be sure to turn off power when working on or near the

electrical system of the heater. Never touch electrical
components with wet hands or when standing in water.

When replacing fuses always use the correct size for the
circuit, see tables on page 11.

The model and rating plates on page 6 interprets certain

markings into useful information. Both of these references should
be used to identify the heater, its components and optional
equipment.

2. The installation must conform with these instructions and the

local code authority having jurisdiction and the requirements
of the power company. In the absence of local codes, the
installation must comply with the latest editions of the National
Electrical Code, NFPA 70 or the Canadian Electrical Code CSA
C22.1. The National Electrical Code may be ordered from:
National Fire Protection Association, 1 Batterymarch Park,
Quincy, MA 02269. The Canadian Electrical Code is available
from the Canadian Standards Association, 8501 East Pleasant
Valley Road, Cleveland, OH 44131.

3. If after reading this manual you have any questions or do not

understand any portion of the instructions, call the toll free
number listed on the back cover of this manual for technical
assistance.

A sample rating plate is shown on page 6 of this manual. In

order to expedite your request, please have full model and serial
number available for the technician.

4. Carefully plan your intended placement of the water heater.

Examine the location to ensure the water heater complies with
the “Locating the New Water Heater” section in this manual.

Installation and service of this water heater requires ability

equivalent to that of a licensed tradesman or qualied agency
(page 2) in the eld involved. Plumbing and electrical work
are required.

4

DIMENSIONS AND CAPACITIES DATA

HOT
CONNECTION

8"

ANODE
ROD

COLD
CONNECTION

C

A

B

FIGURE 1

TABLE 1 - ROUGH-IN DIMENSIONS

Capacity A B C

US Gals. Litres Inches cm Inches cm Inches cm Lbs. Kg.

66 250 60.13 153 52.75 134 22 56 146 66.22

80 303 60.50 154 52.25 133 24 61 174 78.93

119 450 61.38 156 54.38 138 28 71 268 121.56

Approx.

Shipping Weight

TABLE 2 - RECOVERY CAPACITIES

Element
Wattage

(Upper/Lower)

NON-SIMULATANEOUS

3000/3000 GPH 34 30 23 20 17 15 14 12 11 10 10

4000/4000 GPH 45 41 30 27 23 20 18 16 15 14 13

4500/4500 GPH 51 46 34 30 25 23 20 18 17 15 14

5000/5000 GPH 56 51 38 34 28 25 23 20 19 17 16

SIMULATANEOUS OPERATION

3000/3000 GPH 68 61 45 41 34 30 27 24 23 20 19

4000/4000 GPH 90 81 60 54 45 41 36 32 30 27 26

4500/4500 GPH 101 91 68 61 51 46 41 36 34 30 29

5000/5000 GPH 11 3 101 75 68 56 51 45 41 38 34 32

Recovery capacities at 100° F rise equal: for non-simultaneous element operation = 4.1 gal. x KW of one element; for simultaneous element operation = 4.1 gal. x 2/3 KW of
both elements. For other rises multiply element KW as previously explained by 410 and divide by temperature rise. Full load current for single phase = total watts : voltage.

U.S. Gallons/Hr and Litres/Hr at TEMPERATURE RISE INDICATED

INPUT

KW

F° 36F° 40F° 54F° 60F° 72F° 80F° 90F° 100F° 108F° 120F° 126F°
C° 20C° 22.2C° 30C° 33.3C° 40C° 44.4C° 50C° 55.5C° 60C° 66.6C° 70C°

3.0 LPH 128 115 85 77 64 58 51 46 43 38 37

4.0 LPH 170 153 114 102 85 77 68 61 57 51 49

4.5 LPH 192 173 128 11 5 96 86 77 69 64 58 55

5.0 LPH 213 192 142 128 107 96 85 77 71 64 61

6 LPH 256 230 170 153 128 115 102 92 85 77 73

8 LPH 341 307 227 205 170 153 136 123 114 102 97

9 LPH 384 345 256 230 192 173 153 138 128 115 11 0

10 LPH 426 384 284 256 213 192 170 153 142 128 122

5

APPROVALS

All models are listed by

Underwriters Laboratories Inc.

MODEL AND RATING

COMMERCIAL STORAGE

TANK WATER HEATER

22U1

MODEL NUMBER

PHASE

1 PH 3 PH

WATTS
UPPER

WATTS

LOWER

RATED MEASURED

VOLTS - AC

TOTAL WATTS CONNECTED

INTERLOCK SIMULTANEOUS CAPACITY US GAL STANDBY LOSS

1 PH / 3 PH

SERIAL NUMBER

CIRCUIT

MAX WORKING
PRESSURE PSI

%

®

ITEM ID / PART NUMBER

WATTS

LLC

6

FEATURES AND COMPONENTS

ANODE

COLD

ELECTRICAL

JUNCTION BOX

(ACCESS PANEL)

ACCESS

PANELS

DRAIN VA LVE

INSTALL SUITABLE DRAIN PANS UNDER WATER HEATERS
TO PREVENT DAMAGE DUE TO LEAKAGE. REFER TO WATER
HEATER LOCATION ON PAGE 8.

INSTALL THERMAL
EXPANSION TANK
IF CHECK VALVE OR
PRESSURE REDUCING
VALVE IS USED IN
SUPPLY LINE.

INSTALL VACUUM RELIEF
IN COLD WATER INLET
LINE AS REQUIRED BY
LOCAL CODES.

FIGURE 2

7

LOCATING THE NEW WATER HEATER

FACTS TO CONSIDER ABOUT THE LOCATION

The water heater should be located as close as possible
to/or centralized to the water piping system. The water
heater should be located in an area not subject to freezing
temperatures.

The water heater should be located in an area where leakage
of the tank or connections will not result in damage to the area
adjacent to the heater or to lower oors of the structure.

When such locations cannot be avoided, a suitable drain pan
should be installed under the heater.

Such pans should be at least two inches deep, have a
minimum length and width of at least two inches greater
than the diameter of the heater and should be piped to an
adequate drain.

Drain pans suitable for these water heaters are available from
your distributor or A.O. Smith Water Heater Parts Fulllment,
125 Southeast Parkway, Franklin, TN 37068.

Water heater life depends upon water quality, water pressure
and the environment in which the water heater is installed. Water
heaters are sometimes installed in locations where leakage may
result in property damage, even with the use of a drain pan piped
to a drain. However, unanticipated damage can be reduced or
prevented by a leak detector or water shut-off device used in
conjunction with a piped drain pan. These devices are available
from some plumbing supply wholesalers and retailers, and detect
and react to leakage in various ways:

• Sensors mounted in the drain pan that trigger an alarm or turn
off the incoming water to the water heater when leakage is
detected.

• Sensors mounted in the drain pan that turn off the water
supply to the entire home when water is detected in the
drain pan.

• Water supply shut-off devices that activate based on the water
pressure differential between the cold water and how water
pipes connected to the water heater.

• Devices that will turn off the gas supply to a gas water heater
while at the same time shutting off its water supply.

CLEARANCES

A minimum clearance of 4” must be allowed for access to
replaceable parts such as thermostats, drain valve and
relief valve.

Adequate clearance for servicing this water heater should
be considered before installation, such as changing the
anodes, etc.

8

INSTALLATION

REQUIRED ABILITY

Installation and service of this water heater requires ability equivalent
to that of a qualied installer or service agency (page 2) in the
eld involved. Plumbing and electrical work is required.

GENERAL

The installation must conform with these instructions and the local
code authority having jurisdiction and the requirements of the power
compa n y. In the a b s ence of lo c a l co d e s , the i nstallat i o n must c o m p ly
with the latest editions of the National Electrical Code, NFPA 70 or
the Canadian Electrical Code CSA C22.1. The National Electrical
Code may be ordered from: National Fire Protection Association,
1 Batterymarch Park, Quincy, MA 02269. The Canadian Electrical
Code is available from the Canadian Standards Association, 8501
East Pleasant Valley Road, Cleveland, OH 44131.

Do NOT test electrical system before heater is lled with water, follow
the START UP procedure in the OPERATION section of this manual.

The principal components of the heater are identified in the
Features and Components illustrations on page 7.

CONTAMINATED WATER

This water heater shall not be connected to any heating system(s)
or component(s) used with a non-potable water heating appliance.

Toxic chemicals, such as those used for boiler treatment shall not
be introduced into this system.

CIRCULATING PUMP

Field installed circulating pumps should be of all bronze
construction.

INSULATION BLANKETS

Insulation blankets are available to the general public for
external use on electric water heaters but are not necessary with
this product. The purpose of an insulation blanket is to reduce
the standby heat loss encountered with storage tank heaters.
Your water heater meets or exceeds the EPACT and ASHRAE/
IES 90.1 standards with respect to insulation and standby loss
requirements, making an insulation blanket unnecessary.

Should you choose to apply an insulation blanket to this heater,
you should follow these instructions below. Failure to follow
these instructions can result in fire, serious personal injury,
or death.

• Do not cover the temperature and pressure relief (T & P) valve
with an insulation blanket.

• 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 for placement on
the blanket directly over the existing labels.

MIXINGVALVEUSAGE:

Water heaters are intended to produce hot water. Water heated to
a temperature which will satisfy space heating, clothes washing,
dish washing, cleaning and other sanitizing needs can scald and
permanently injure you upon contact. Some people are more likely
to be permanently injured by hot water than others. These include
the elderly, children, the inrm, or physically/developmentally
disabled. If anyone using hot water in your home ts into one of
these groups or if there is a local code or state law requiring a
maximum water temperature at the hot water tap, then you must
take special precautions. In addition to using the lowest possible
temperature setting that satises your hot water needs, a means
such as a MIXING VALVE, should be used at the hot water taps
used by these people or at the water heater.

MIXING VALVES f o r re ducing po i n t of us e temperat u r e are av ailabl e
and are to be set at a maximum of 125 degree F. Consult a qualied
installer or service agency. Follow all manufacturer’s Instructions
for installation of these valves. Before changing the factory setting
on the thermostat, read the “Temperature Regulation” section in
this manual.

TEMPERATURE-PRESSURE RELIEF VALVE

This water heater is provided with a properly rated/sized and
certied combination temperature - pressure relief valve by the
manufacturer. The valve is certied 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 valve must meet the requirements of local
codes, but not less than a combination temperature and pressure
relief valve rated/sized and certied as indicated in the above

9

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 capac it y
not less than the water heater Btu/hr or KW input rate as shown on
the water heater’s model rating plate.

For safe operation of the water heater, the temperature and 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 only within 6
inches (15.2 cm) above, or at any distance below the structural oor.
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.

No valve or other obstruction is to be placed between the 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.

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 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.

The temperature-pressure relief valve must be manually operated
at least once 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
can cause 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.

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.

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 should 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.

10

ELECTRICAL

GENERAL

The installation must conform with these instructions and the local
code authority having jurisdiction and the requirements of the power
company. In the absence of local codes, the installation must comply
with the current editions of the National Electrical Code, NFPA 70 or
the Canadian Electrical Code CSA C22.1.

An electrical ground is required to reduce risk of electrical shock
or possible electrocution. The water heater should be connected
to a separate grounded branch circuit with over-current protection
and disconnect switch. The water heater should be grounded in
accordance with national and local codes.

Voltage applied to the heater should not vary more than +5% to -10%
of the model and rating plate marking for satisfactory operation.

DO NOT ENERGIZE THE BRANCH CIRCUIT FOR ANY REASON
BEFORE THE WATER HEATER TANK IS FILLED WITH WATER.
DOING SO WILL CAUSE THE HEATING ELEMENTS TO BURN
OUT AND VOID WARRANTY.

The factory wiring should be connected to the branch circuit wiring
within the provided junction box. The water heater should be
connected to a separate, grounded, branch circuit with overcurrent
protection and disconnect switch. The water heater should be
grounded in accordance with national and local codes.

BRANCH CIRCUIT

The branch circuit wire size should be established through reference
to the current edition of NFPA-70, the National Electrical Code
or other locally approved source in conjunction with the heater
amperage rating. For convenience, portions of the wire size tables
from the Code are reproduced here. The branch circuit should be
sized at 125 percent of the heater rating and further increase wire
size as necessary to compensate for voltage drop in long runs.

CALCULATING AMPERAGE/OVERCURRENT PROTECTION

The water heaters come from the factory in two congurations:

1. Two wire T-6 circuit for dual element water heater equipped with
a single high limit control and single phase power input.

2. Four wire T-4 circuit for dual element water heater equipped with
two high limit controls and single phase power input.

This is an example of calculating heater amperage for both types
of element operation. From this, the branch circuit conductor and
overcurrent protection sizing can be established.

The example (T-4) is of a single-phase 240 volt unit with two, 3 kw
elements. Check the water heater model and rating plate for actual
specications and substitute those values in the following.

TABLE 3

Non-simultaneous:
(T6 - Circuit)

Simultaneous:
(T4 - Circuit)

3000 ÷ 240 = 12.5 amps* 6000 ÷ 240 = 25 amps*
*NOTE: as a single-phase non-

simultaneous unit.

*NOTE: as a single-phase
simultaneous unit.

The rating of the overcurrent protection should be computed on the
ba s i s of 125 pe rcent of the t otal c o n n ected lo a d ampera g e . W h e r e the
standard ratings and settings do not correspond with this computation,
the next higher standard rating or setting should be selected.

PortionofTable310-16(NFPA-70)follows:

Allowable Ampacities of Insulated Copper Conductors. Not more
than three conductors in Raceway or Cable or Direct Burial (Based
on Ambient Temperature of 30° C, 86° F).

These ampacities relate only to conductors described in Table
310-16 in Code.

For ambient temperatures over 30° C (86° F), see Correction
Factors, Note 13 in Code.

TABLE 4

Size

AMG

MCM

RUW, (14-2), T, TW, UF

18

16
14
12
10

8

6
4
3

Temperature Rating of Conductor

See Table 310-16 in Code

60°C

(140°F)

Types:

- - -

- - ­15

20
30
40

55

70

80

RH, RHW, RUH, (14-2),

THW, THWN, XHHW, USE

75°C

(167°F)

Types:

- - -

- - ­15

20
30

45
65
85

100

PortionofTable310-18follows:

Allowable Ampacities of Insulated Aluminum and Copper -Clad
Aluminum Conductors.

Not more than three conductors in Raceway or Cable or Direct Burial
(Based on Ambient Temperature of 30° C, 86° F. These ampacities
relate only to conductors described in Table 310-18 in Code.

For ambient temperatures over 30° C (86° F), see Correction Factors,
Note 13 in Code.

TABLE 5

Size

AMG
MCM

RUW, (12-2), T, TW, UF

12
10

8

6
4
3
2
1

Temperature Rating of Conductor

See Table 310-18 in Code

60°C

(140°F)

Types:

15
25

30
40

55
65
75
85

RH, RHW, RUH, (12-2),

THW, THWN, XHHW, USE

75°C

(167°F)

Types:

15
25

40

50
65
75

90

100

11

WIRING DIAGRAMS

T-6

208 or 240 VOLT

NON-SIMULTANEOUS

SINGLE PHASE OPERATION

RED

BLACK

YELLOW

BLUE

BLACK

RED

BLACK

BLACK

BLACK

RED

RED

RED

BLACK

RED

BLACK

T-4

208 or 240 VOLT

SIMULTANEOUS OPERATION

SINGLE PHASE OPERATION

GND

GREEN

GND

GREEN

L1

L2

SUPPLY LEADS

L1

L2

SUPPLY LEADS

FIGURE 3

12

OPERATION

GENERAL

Refer to the Features and Components section of this manual (page

7) for the location of components mentioned in the instructions
that follow.

NEVER turn on power to the water heater without being certain the
water heater is lled with water and a temperature and pressure
relief valve is installed in the relief valve opening.

DO NOT TEST ELECTRICAL SYSTEM BEFORE HEATER IS
FILLED WITH WATER. FOLLOW FILLING AND START-UP
INSTRUCTIONS IN OPERATION SECTION.

FILLING THE WATER HEATER

INITIAL START UP

The following checks should be made by the installer when the heater
is placed into operation for the rst time.

1. Turn off the electrical disconnect switch.

2. Open the front panel or top access cover, check all water and
electrical connections for tightness. Also check connections on top
and or sides of heater. Repair water leaks and tighten electrical
connections as necessary.

3. Depress the red manual reset button on each Thermostat/ECO
combination control. (See Figure 5, or Figure 6)

4. Turn on the electrical disconnect switch.

5. Observe the operation of the electrical components during the rst
heating cycle. Use care as the electrical circuits are energized.

6. Close the front panel or top access cover.

Temperature control and contactor operation should be checked by
allowing heater to come up to temperature and shut off automatically.
Use care as the electrical circuits are energized.

DRAINING THE WATER HEATER

The water heater must be drained if it is to be shut down and exposed
to freezing temperatures. Maintenance and service procedures may
also require draining the heater.

1. Turn off the electrical disconnect switch.

2. Open a hot water valve until the water is cool, then close the
supply water inlet valve to heater.

3. Attach hose to outlet opening of drain valve and direct end to drain.

4. Open a nearby hot water faucet and the heater drain valve.

5. If the heater is being drained for an extended shutdown, it is
suggested the drain valve be left open during this period. The
hose may be removed.

Follow FILLING instructions when restoring hot water service.

1. Turn off the electrical disconnect switch.

2. Close the water heater drain valve.

3. Open a nearby hot water faucet to permit the air in the system
to escape.

4. Fully open the cold water inlet pipe valve allowing the heater and
piping to be lled.

5. Close the hot water faucet as water starts to flow. The
heater is now ready for STARTUP and TEMPERATURE
REGULATION.

INSTALLATION

13

TEMPERATURE REGULATION

THE WATER HEATER IS EQUIPPED WITH AN ADJUSTABLE
THERMOSTAT TO CONTROL WATER TEMPERATURE. HOT
WATER AT TEMPERATURES DESIRED FOR AUTOMATIC
DISHWASHER AND LAUNDRY USE CAN CAUSE SCALDS
RESULTING IN SERIOUS PERSONAL INJURY AND/OR DEATH.
THE TEMPERATURE AT WHICH INJURY OCCURS VARIES WITH
THE PERSON’S AGE AND TIME OF EXPOSURE. THE SLOWER
RESPONSE TIME OF CHILDREN , AGED OR DISABLED PERSONS
INCREASES THE HAZARD TO THEM. NEVER ALLOW SMALL
CHILDREN TO USE A HOT WATER TAP, OR TO DRAW THEIR OWN
BATH WATER. NEVER LEAVE A CHILD OR DISABLED PERSON
UNATTENDED IN A BATHTUB OR SHOWER.

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 thermostats (See Figure 4) be set for the lowest
temperature which satises your hot water needs. This will also
provide the most energy efcient operation of the water heater.

Figure 4 shows the approximate time-to-burn relationship for
normal adult skin. The thermostats on your water heater have a
linear relationship between degrees of angular rotation and the
corresponding change in temperature. Thus rotating the temperature
adjustment indicator 30 angular degrees will result in a 10 degree
Fahrenheit change in water temperature.

Water Temperature

°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

(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)

FIGURE 4

TEMPERATURE ADJUSTMENT

The thermostats are adjustable from approximately 120°F (49°C)
(lowest setting) to 181°F (83°C) (highest setting) (See Figure 5).
These thermostats are set from the factory at approximately the
140°F (60°C) setting. The over temperature device (ECO high limit)
attached to each thermostat has a manual reset.

T-4 THERMOSTAT

(UPPER & LOWER)

T-6 THERMOSTAT

(UPPER)

T-6 THERMOSTAT

(LOWER)

FIGURE 5

NOTE: It is not necessary to adjust the upper thermostat for a dual
element unit. However, if it is adjusted above the factory set point
140°F (60°C) it is recommended that it not be set higher than the
lower thermostat setting.

To change the temperature setting:

1. DANGER: Turn off the heater electrical supply. Do not attempt
to adjust thermostat with power on.

2. Remove the upper and/or lower element access panel. Do
not remove the plastic personnel protectors covering the
thermostats. The thermostat is factory pre-set at 140°F (60°C).

3. Using a at tip screwdriver, rotate the adjusting knob to the
desired temperature setting.

4. Replace th e ac c e s s panels, an d turn o n heater el e c t r i c a l suppl y.

14

MAINTENANCE

GENERAL

Periodically the drain valve should be opened and the water
allowed to run until it flows clean. This will help to prevent
sediment buildup in the tank bottom.

Periodically check the temperature and pressure relief valve
to ensure that it is in operating condition. Lift the lever at the
top of the valve several times until the valve seats properly
and operates freely.

Water heater maintenance includes periodic tank flushing and
cleaning, and removal of lime scale from the heating element.

The heater tank is equipped with an anode rod to aid in
corrosion control.

ANODE ROD INSPECTION

The anode rod is used to protect the tank from corrosion. Most hot
water tanks are equipped with an anode rod. The submerged rod
sacrices itself to protect the tank. Instead of corroding tank, water
ions attack and eat away the anode rod. This does not affect water’s
taste or color. The rod must be maintained to keep tank in operating
condition.

Anode deterioration depends on water conductivity, not necessarily
water condition. A corroded or pitted anode rod indicates high water
conductivity and should be checked and/or replaced more often than
an anode rod that appears to be intact. Replacement of a depleted
anode rod can extend the life of your water heater. Inspection should
be conducted by a qualied technician, and at a minimum should be
checked annually after the warranty period.

Articially softened water is exceedingly corrosive because the
process substitutes sodium ions for magnesium and calcium ions.

The use of a water softener may decrease the life of the water
heater tank.

The anode rod should be inspected after a maximum of three years
and annually thereafter until the condition of the anode rod dictates
its replacement.

NOTE: Articially softened water requires the anode rod to be
inspected annually.

15

TROUBLESHOOTING CHECKLIST

CHECKLIST

Before calling for service, check the following points to see if the
cause of trouble can be identied and corrected.

Reviewing this checklist may eliminate the need of a service call
and quickly restore hot water service. See Figure 2 on page 7 in this
manual to identify and locate water heater components.

NOT ENOUGH OR NO HOT WATER

1. Be certain the electrical disconnect switch serving the water heater
is in the ON position.

2. Check the fuses.

• The electrical disconnect switch usually contains fuses.

3. If the water was excessively hot, and is now cold, the high limit
switch may have activated.

• See the Temperature Regulation section of this manual for

more information on how to reset the ECO high limit controls.

4. The capacity of the heater may have been exceeded by a large
demand for hot water.

• Large demands require a recovery period to restore water

temperature.

5. Cooler incoming water temperature will lengthen the time required
to heat water to the desired temperature.

6. Look for hot water leakage.

7. Sediment or pipe scale may be affecting water heater operation.

ABNORMAL SOUNDS

1. Sediment or lime scale accumulations on the elements causes
sizzling and hissing noises when the heater is operating.

• The sounds are normal, however, the tank bottom and

elements should be cleaned. See the Maintenance section
of this manual.

WATER LEAKAGE IS SUSPECTED

Refer to Leakage Checkpoint on the following page 17.

1. Check to see if the heater drain valve is tightly closed.

2. If the outlet of the relief valve is leaking it may represent:

• Excessive water temperature.

• Faulty relief valve.

• Excessive water pressure.

3. Excessive water pressure is the most common cause of relief valve
leakage. It is often caused by a “closed system”. See “Closed
Water Systems” and “Thermal Expansion” in the Installation
section of this manual for more information.

4. Examine the area around the element for gasket leakage.

• Tighten the elements or, if necessary, follow the WATER

AND LIME SCALE REMOVAL procedure to replace the
gaskets.

IF YOU CANNOT IDENTIFY OR CORRECT THE SOURCE OF
MALFUNCTION

1. Turn the power supply to the water heater off.

2. Close the supply water inlet valve to the heater.

3. Contact a Qualied Service Agency in your area. Call the toll free
phone number on the back cover of this Instruction Manual for
assistance in locating a service agency in your area.

REPLACEMENT PARTS

Call the toll free phone number on the back cover of this Instruction
Manual for assistance in locating replacement parts.. When ordering
parts, specify complete model no., serial no., (see rating plate),
quantity and name of part desired. Standard hardware items should
be purchased locally.

16

LEAKAGE CHECKPOINTS

Instructions: Use this illustration as a guide when checking for sources of water leakage. You or your dealer may be able to correct what
appears to be a problem. NOTE:CoverandInsulationshownremovedtorevealtanktop.

Where possible remove or lift top cover to
examine threads of ttings installed into tank
for evidence of leakage. Correct tting leaks
as necessary.

Water leaks at the elements may be due

to:

1. Defective element which leaks at
terminals or thru flange. Replace
element*.

2. Looseelement/gasketleak:

 (a)Screw-in type: tighten with 1-1/2”

socket wrench. If leak continues,
remove element*, discard gasket
and clean thread areas.Apply
nonhardening Permatex Number 2
to thread areas, install new gasket

andscrewelementintottinguntil

it seats. Tighten 1/2 to 3/4 turn with
wrench.

 (b)Flange type: tighten screw with

wrench. If leak continues remove
element* and discard gasket. Clean
gasket seating areas and re-install
element with new gasket. A new
element may be required where
threads have become rusted or
damaged, preventing tightening.

All water which appears at the water

heaterb o t t o m o r o nthesurrou n d i n g  o o r

may be caused by condensation, loose
connections or relief valve operation
and leakage. Do not replace the water
heater until full inspection of all potential
leak points is made and corrective steps
taken to stop the leak. Leakage from other
appliances, water lines or ground (see
page 16) should also be suspected until
proven otherwise.

Relief Valve

Anode Rod (Some Models)

FIGURE 6

To Open Drain

Condensation and dripping may appear
on pipes when cold water temperature is

low.Pipettingmaybeleaking.

Relief valve operation and leakage
may be due to water expansion during
heating cycle or foreign material on seat
of valve. If the valve is not piped to an
open drain the released water could be
mistaken for a leaking heater. To check
where threaded material between jacket
opening and swab spud area. Remove
valve* if indicated and repair with pipe
joint compound.

To Open Drain

Water on the side of the tank may
be condensation due to the panel or
insulation not being in place.

Drain valve leakage could be from the
valve itself.* To check for leakage where
threaded portion enters tank, insert Q-tip
or similar absorbent material between
jacket opening and valve to swab spud
area. Remove valve* if leak is indicated
and repair with pipe joint compound.

*Contact your dealer as it is necessary to
shut off electricity and drain tank to perform
procedure.

17

COMMERCIAL

WATER HEATER

LIMITED WARRANTY

WARRANTY

EFFECTIVE

For 3 Years, in the event of a tank leak, we will repair or, at our

discretion, replace the defective water heater.

For 1 Year, in the event of part failure, we will repair or, at our

discretion, replace the defective part.

We warrant this product against defects in materials or
workmanship as described in this document if installed within
the United States or Canada and provided the product remains
at its original place of installation.

Warranty coverage begins the date of installation OR the date of
manufacture if installation cannot be veried.

WHAT'S COVERED

Subject to these terms, in the event of defect in materials and/
or workmanship resulting in a tank leak during the rst three
years, we will:

• Replace the water heater should the tank leak.

Subject to these terms, in the event of a defect in materials and/or
workmanship appearing during the rstyear, we will:

• Repair or, at our discretion, replace any part of the water
heater covered under this limited warranty excluding parts
subject to normal maintenance (Example: non-electronic
anode rod, lter, etc)

Service/labor, shipping, delivery, installation, handling or any
other costs are not covered at any time under this warranty.

Any replacement part or product will be warranted only for
the unexpired portion of the original water heater’s limited
warranty period.

If an identical model is no longer available due to a change in law,
regulation, or standard, we will replace the product with one having
comparable capacity and input. In these instances, the owner will
have the option of paying the difference between what was paid for
the original model and the new model with the additional features,
or receiving a refund of the portion of the purchase price, on a
pro-rata basis allocable to the unexpired portion of the warranty.

WHAT'S NOT COVERED

• Problems caused by improper: gas supply line sizing, gas type,
venting, connections, combustion air, voltage, wiring, or fusing

• Failure to follow applicable codes

• Failure to follow printed instructions

• Abuse, misuse, accident, re, ood, Acts of God

• Improper installation, sizing, delivery, or maintenance

• Claims related to rust, noise, smell, or taste of water

• Failure to conduct authorized factory start up if required

• Alterations to the water heater

• Non-outdoor heaters installed outdoors

• Damages due to a failure to allow for thermal expansion

• Heat exchanger failure due to lack of adequate / proper supply
of water

• Heaters moved from their original location

• Service trips to explain proper installation, use, or maintenance
of the product/unit or to describe compliance requirements
under applicable codes and regulations

• Charges related to accessing your heater including but not
limited to door/wall removal, equipment rental, etc.

• Replacement parts after expiration of this warranty

LIMITATIONS

NOTWITHSTANDING ANYTHING ELSE TO THE CONTRARY,
THIS IS YOUR SOLE AND EXCLUSIVE WARRANTY.
ALL OTHER WARRANTIES INCLUDING A WARRANTY
OF MERCHANTABILITY OR FITNESS FOR PARTICULAR
PURPOSE ARE EXPRESSLY DISCLAIMED. SELLER SHALL
NOT BE LIABLE FOR ANY CONSEQUENTIAL, INCIDENTAL,
SPECIAL, PUNITIVE OR OTHER INDIRECT DAMAGES. TOTAL
LIABILITY ARISING AT ANY TIME SHALL NOT EXCEED THE
PURCHASE PRICE PAID WHETHER BASED ON CONTRACT,
TORT, STRICT LIABILITY OR ANY OTHER LEGAL THEORY.

SERVICEINQUIRIES:

For service inquiries call the telephone number listed below. Be prepared to provide the following information:
name, address, and telephone number; the model and serial number of the water heater; proof of installation; and a clear description
of the problem.

For your records, fill in the product:

Serial: ___________________
Model: ___________________

U.S. Customers:

A. O. Smith Corporation

500 Tennessee Waltz Parkway

Ashland City, Tennessee 37015

800-527-1953

www.hotwater.com

18

CanadianCustomers:

P. O. Box 310 – 768 Erie Street

Stratford (Ontario) N5A 6T3

800-265-8520

REPAIR PARTS LIST

Now that you have purchased this water heater, should a need ever
exist for repair parts or service, simply contact the company it was
purchased from or direct from the manufacturer listed on the rating
plate on the water heater.

Selling prices will be furnished on request or parts will be shipped
at prevailing prices and you will be billed accordingly.

The model number of your Water Heater will be found on the rating
plated located above the lower access panel.

KEY

NO.

1 Extension Nipple

2 Combo Dip Tube

3 Primary Anode Rod

4 T&P Valve

5 Element Gasket

6 Upper Element

7 Thermostat Bracket

8 Upper Thermostat w/Hi Limit

9 Terminal Protector

10 Upper Access Panel

11 Lower Access Panel

12 Lower Thermostat w/Hi Limit

13 Lower Element

14 Brass Drain Valve

15 Drain Pan

PART DESCRIPTION

10

Be sure to provide all pertinent facts when you call or visit.

WHEN ORDERING REPAIR PARTS, ALWAYS GIVE THE
FOLLOWING INFORMATION:

• MODEL NUMBER

• VOLTAGE AND ELEMENT WATTAGE

• SERIAL NUMBER

• PART DESCRIPTION

1

4

5

6

7

14

2

3

8

9

11

FIGURE 7

19

12

13

15

FIGURE 8

TABLE 6 - COPPER SHEATH ELEMENT AND WATTAGE CHART

K.W. ELEMENT WATTAGE

3.0 3000 9003956115 9001879005

3.5 3500 9000092015 9003948115

4.0 4000 9003951115 9003956115

4.5 4500 9002645005 9000092015

5.0 5000 9004688105 9003957005

5.5 5500 --- 9003951115

208V 240V

PART NO. PART NO.

20

NOTES

21

NOTES

22

NOTES

23

500 Tennessee Waltz Parkway, Ashland City, TN 37015

Copyright © 2016 A. O. Smith Water Heater Company, All rights reserved.

www.hotwater.com

Tech Support: 800-527-1953

Parts: 800-433-2545

24