AO Smith Water Heater AOSRE50400 User Manual

instruction manual

residential electric

2.5 Gallon 120 volt

water heater

for potaBle water

heatinG onlY

not suitaBle for

space heatinG

listed

all technicaland warrantY questions: SHOULD BE DIRECTED TO THE LOCALDEALER FROM WHOM THE WATER HEATER WAS

PURCHASED. IFYOUARE UNSUCCESSFUL, PLEASE WRITETOTHE COMPANYLISTED ONTHE RATING PLATE ONTHE WATER HEATER.

Keep this manual in the pocKet on heater for future reference

when ever maintenance adjustment or service is required.

PRINTED 0707

ꢀ85834-000

ꢀ

safe installation, use and service

Your safety and the safety of others is extremely important in the installation, use, and servicing of this water heater.

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.

danGerindicatesanimminentlyhazardous

situation which, if not avoided, could result

in death or injury.

danGer

warninG indicates a potentially hazardous

situation which, if not avoided, could result

in death or injury.

warninG

caution indicates a potentially hazardous

situation which, if not avoided, may result

in minor or moderate injury.

caution

caution used without the safety alert

symbol indicates a potentially hazardous

situation which, if not avoided, could result

in property damage.

caution

all safety messages will generally tell you about the type of hazard, what can happen if you do not follow the safety message,

and how to avoid the risk of injury.

the california safe drinking water and toxic enforcement act requires the Governor of california to publish a list of substances

known to the state of california to cause cancer, birth defects, or other reproductive harm, and requires businesses to warn of

potential exposure to such substances.

this product contains a chemical known to the state of california to cause cancer, birth defects, or other reproductive harm. this

appliance can cause low level exposure to some of the substances listed, including formaldehyde.

important definitions

•

Qualiﬁed Installer: A qualiﬁed installer must have ability equivalent to a licensed tradesman in the ﬁelds of plumbing and electrical

installation of these appliances. This would include a thorough understanding of the requirements of the National Electrical Code and

applicable local electrical and plumbing codes (and tools necessary to conﬁrm proper installation and operation of the water heater) as

they relate to the installation of electric water heaters. The qualiﬁed installer must have a thorough understanding of the water heater

Instruction Manual.

service agency: A service agency also must have ability equivalent to a licensed tradesman in the ﬁelds of plumbing and electrical

installation of these appliances. This would include a thorough understanding of the requirements of the National Electrical Code and

applicable local electrical and plumbing codes (and tools necessary to conﬁrm proper installation and operation of the water heater) as

they relate to the installation of electric water heaters. The service agency must have a thorough understanding of the water heater

Instruction Manual.

ꢁ

General safetY

introduction

thank You for purchasing this water heater. Properly installed and

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 code requirements

follow NFPA-70, the National Electrical Code (current edition),

which may be ordered from: National Fire ProtectionAssociation,

1 Batterymarch Park, Quincy, MA 02269.

maintained, it should give you years of trouble free service.

Abbreviations Found In This Instruction Manual:

•

ANSI - American National Standards Institute

ASME - American Society of Mechanical Engineers

NEC - National Electrical Code

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

understand any portion of the instructions, call the local utility or

the manufacturer whose name appears on the rating plate.

NFPA - National Fire Protection Association

UL - Underwriters Laboratories Inc.

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

INSTALLATION OR SERVICE OF THIS WATER HEATER

REQUIRES ABILITY EQUIVALENT TO THAT OF A LICENSED

TRADESMAN IN THE FIELD INVOLVED. PLUMBING

AND ELECTRICAL WORK ARE REQUIRED.

preparinG for the installation

1. Read the “General Safety” section of this manual ﬁrst and then

the entire manual carefully. If you don’t follow the safety rules,

the water heater will not operate properly. It could cause DEATH,

SERIOUS BODILY INJURY, AND/OR PROPERTY DAMAGE.

Examine the location to ensure the water heater complies with the

“Facts to Consider About the Location” section in this manual.

5. For California installation this water heater must be braced,

anchored, or strapped to avoid falling or moving during an

earthquake. See instructions for correct installation procedures.

Instructions may be obtained from California Ofﬁce of the State

Architect, 400 P Street, Sacramento, CA 95814.

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

understand. 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.

6. Massachusetts Code requires this water heater to be installed in

accordance with Massachusetts 248-CMR 2.00: State Plumbing

Code and 248-CMR 5.00.

taBle of contents

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

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

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

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

TABLE OF CONTENTS................................................................................................................................................................................................ 4

TYPICAL INSTALLATION............................................................................................................................................................................................. 5

MIXING VALVE USAGE............................................................................................................................................................................................... 5

LOCATING THE NEW WATER HEATER..................................................................................................................................................................... 6

Facts to Consider About Location ........................................................................................................................................................................ 6

Insulation Blankets ............................................................................................................................................................................................... 6

IMPORTANT SAFETY INSTRUCTIONS...................................................................................................................................................................... 6

INSTALLING THE NEW WATER HEATER .................................................................................................................................................................. 7

Mounting............................................................................................................................................................................................................... 7

Water Piping......................................................................................................................................................................................................7-8

Water Piping Pressure Test.................................................................................................................................................................................. 8

Temperature-Pressure Relief Valve...................................................................................................................................................................8-9

Filling the Water Heater........................................................................................................................................................................................ 9

WIRING DIAGRAM .................................................................................................................................................................................................... ꢀ0

WIRING .......................................................................................................................................................................................................................ꢀꢀ

TEMPERATURE REGULATION ................................................................................................................................................................................ ꢀꢁ

Temperature Adjustment .................................................................................................................................................................................... ꢀꢁ

FOR YOUR INFORMATION....................................................................................................................................................................................... ꢀ3

Thermal Expansion ............................................................................................................................................................................................ ꢀ3

Strange Sounds.................................................................................................................................................................................................. ꢀ3

Operational Conditions....................................................................................................................................................................................... ꢀ3

Water Odor......................................................................................................................................................................................................... ꢀ3

“Air” in Hot Water Faucets.................................................................................................................................................................................. ꢀ3

High Water Temperature Shut Off System ......................................................................................................................................................... ꢀ3

PERIODIC MAINTENANCE....................................................................................................................................................................................... ꢀ4

Anode Rod Inspection........................................................................................................................................................................................ ꢀ4

Temperature-Pressure Relief Valve Operation................................................................................................................................................... ꢀ4

Draining.............................................................................................................................................................................................................. ꢀ4

Removing Front Panel...................................................................................................................................................................................ꢀ4-ꢀ5

Thermostat Removal/Replacement.................................................................................................................................................................... ꢀ5

Element Cleaning/Replacement....................................................................................................................................................................15-16

High Limit Switch Removal and Replacement ................................................................................................................................................... 16

Service ............................................................................................................................................................................................................... 16

LEAKAGE CHECKPOINTS........................................................................................................................................................................................ ꢀ7

TROUBLESHOOTING GUIDELINES......................................................................................................................................................................... ꢀ8

REPAIR PARTS LIST................................................................................................................................................................................................. 19

tYpical installation

fiGure 1.

miXinG valve usaGe

fiGure 2.

HOTTER WATER CAN SCALD:

water (potable) heating: All models are considered suitable for

water (potable) heating only.

Water heaters are intended to produce hot water. Water heated to a

temperature which will satisfy space heating, clothes washing, dish

washing, 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 inﬁrm, or physically/mentally disabled. If anyone using hot water in

your home ﬁts into one of these groups or if there is a local code or state

law requiring a certain temperature water at the hot water tap, then you

must take special precautions. In addition to using the lowest possible

temperature setting that satisﬁes your hot water needs, a means such

as a mixing valve, should be used at the hot water taps used by these

peopleoratthewaterheater. Mixingvalvesareavailablefromyourlocal

plumbing contractor. Consult a Qualiﬁed Installer or Service Agency.

Follow mixing valve manufacturer’s instructions for installation of the

valves. Before changing the factory setting on the thermostat, read the

“Temperature Regulation” section in this manual.

locatinG the new water heater

pan should be installed under the water heater. Drain pans are

facts to consider aBout the location

available from your local plumbing contractor. Such a drain

pan must have a minimum length and width of at least 2 inches

(51 mm) greater than the water heater dimensions and must

be piped to an adequate drain.

Water heater life depends upon water quality, water pressure,

water usage, water temperature, 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 conjunc-

tion 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:

Carefully choose an indoor location for the new water heater,

because the placement is a very important consideration for the

safety of the occupants in the building and for the most economical

use of the appliance.

• Sensors mounted in the drain pan that trigger an alarm or turn off

the incoming water to the water heater when leakage is detected.

Whether replacing an old water heater or putting the water heater

in a new location, the following critical points must be observed:

• Sensors mounted in the drain pan that turn off the water supply to

the entire home when water is detected in the drain pan.

1. Select a location as close as practical or centralized to the point

of use. The water heater should be located in an area not subject

to freezing temperatures.

• Water supply shut-off devices that activate based on the

water pressure differential between the cold water and hot

water pipes connected to the water heater.

2. Selected location must provide adequate clearances for removing

the front cover in order to service parts such as the thermostat,

element, temperature sensor, anode, and high limit reset. Adequate

clearance for servicing this appliance should be considered before

installation, such as operating the relief valve, etc.

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.

3. The water heater should be located so it is not subject to physical

damage by moving vehicles or area ﬂooding.

4. The selected wall or cabinet must be capable of supporting at

least two times the weight of the water heater when ﬁlled with

water (77 lbs).

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.

5. The water heater must be installed in a vertical position with water

inlet and outlet connections facing upwards and easily accessible.

•

Do not cover the temperature and pressure relief (T & P) valve

with an insulation blanket.

Installation of the water heater must be accomplished in such

a manner that if the tank or any connections should leak, the

flow will not cause damage to the structure. For this reason, it

is not advisable to install the water heater in an attic or upper

floor. When such locations cannot be avoided, a suitable drain

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.

important safetY instructions

2. This water heater must be grounded. Connect only to properly

grounded outlet. See GROUNDING INSTRUCTIONS found in the

WIRING section of this manual.

3. Install or locate this water heater only in accordance with the

provided installation instructions.

4. Use this water heater for its intended use as described in this

manual.

5. Do not use an extension cord set with this water heater. If no

receptacle is available adjacent to the water heater, contact a

qualiﬁed electrician to have one properly installed.

6. As with any appliance, close supervision is necessary when used

by children.

7. Do not operate this water heater if it has a damaged cord or plug, if

it is not working properly, or if it has been damaged or dropped.

8. This water heater should be serviced only by qualiﬁed service

personnel. Contact nearest authorized service facility for

examination, repair, or adjustment.

ꢀ. READ ALL INSTRUCTIONS BEFORE USING THIS WATER HEATER.

installinG the new water heater

water to a maximum depth of 2-1/2 inches and be 2 inches wider

than the unit. The pan must also be piped to an adequate drain.

See Figure 3B.

mountinG

mountinG - drYwall (hollow wall)

1. The selected wall or cabinet must be capable of supporting double

the weight of the unit when completely full of water (77 Ibs).

2. The installation area must provide adequate clearances for

removal of the front panel and servicing the unit.

3. Locate the wall studs in the area where the unit is to be

mounted.

4. Cut two sections of 1/2 inch plywood or equivalent material 3

inches in height. The length of each section should be sufficient

to span the width of the wall studs. See Figure 3A.

5. Use appropriately sized nails or wood screws to attach the two

wall supports to the wall as show in Figure 3A.

6. Drill two 13/32 inch holes in the upper wall support NOTE: The

holes must be level.

7. Insert the hollow wall anchors into the drilled holes. Place the

wall bracket over the anchors and screw the two phillips head

screws down tight against the bracket.

fiGure 3B.

water pipinG

mountinG - masonrY wall (solid wall)

1. The selected wall or cabinet must be capable of supporting double

the weight of the unit when completely full of water (77 Ibs).

2. The installation area must provide adequate clearances for

removal of the front panel and servicing the unit.

3. Drill two 13/32 inch holes in the masonry wall. NOTE: The

holes must be level and at least 3-1/2 inches deep.

4. Insert the masonry wall anchors into the drilled holes. Place

the wall bracket over the anchors and screw the two phillips

head screws tight against the bracket.

HOTTER WATER CAN SCALD:

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 inﬁrm, or physically/mentally disabled. If anyone

using hot water in your home ﬁts into one of these groups or if there

is a local code or state law requiring a certain temperature water at

the hot water tap, then you must take special precautions. In addition

to using the lowest possible temperature setting that satisﬁes your

hot water needs, a means such as a mixing valve should be used at

the hot water taps used by these people or at the water heater.

Valves for reducing point of use temperature by mixing cold and

hot water are also available.

fiGure 3a.

mountinG - floor

1. The floor selected must be capable of supporting double the

weight of the unit when completely full of water (77 Ibs).

2. The installation area must provide adequate clearances for

removal of the front panel and servicing the unit.

3. Place a suitable drain pan under the unit. The pan must limit the

Consult a Qualiﬁed Installer or ServiceAgency. Follow manufacturer’s

instructions for installation of the valves. Before changing the factory

setting on the thermostat, read the “Temperature Regulation” section

in this manual.

This water heater shall not be connected to any heating

systems or component(s) used with a non-potable water heating

appliance.

Toxic chemicals, such as those used for boiler treatment shall

not be introduced into this system.

Water supply systems may, because of such events as

high line pressure, frequent cut-offs, the effects of water

hammer among others, have installed devices such

as pressure reducing valves, check valves, back flow

preventers, etc. to control these types of problems. When

these devices are not equipped with an internal by-pass,

and no other measures are taken, the devices cause the

water system to be closed. As water is heated, it expands

(thermal expansion) and closed systems do not allow for

the expansion of heated water.

fiGure 4.

water pipinG pressure test

This section is only for the manufacturer installing the

water heater when the installation is to comply with H.U.D.

Standards.

When testing the water ways, H.U.D. Standards state:

“Water distribution system: All water piping in the water

distribution system shall be subjected to a pressure test.

The test shall be made by subjecting the system to air or

water at 100 psi for 15 minutes without loss of pressure.

when air pressure is used, the water heater shall not

be connected during the test.”

The water within the water heater tank expands as it is heated

and increases the pressure of the water system. If the relieving

point of the water heater’s temperature-pressure relief valve

is reached, the valve will relieve the excess pressure. the

temperature-pressure relief valve is not intended for the

constant relief of thermal expansion. This is an unacceptable

condition and must be corrected.

It is recommended that any devices installed which could create

a closed system have a by-pass and/or the system have an

expansion tank or device to relieve the pressure built by thermal

expansion in the water system. Expansion tanks are available

for ordering through a local plumbing contractor. Contact the

local water supplier and/or a service agency for assistance in

controlling these situations.

note: to protect against untimely corrosion of hot and

cold water fittings, it is strongly recommended that di-

electric unions or couplings be installed on this water

heater when connected to copper pipe.

figure 4 shows the typical attachment of the water piping

to the water heater. the water heater is equipped with 1/2

inch npt water connections.

temperature-pressure relief valve

note: if using copper tubing, solder tubing to an adapter

before attaching the adapter to the cold water inlet

connection. do not solder the cold water supply line directly

to the cold water inlet, it will harm the dip tube and damage

the tank.

This heater is provided with a properly certified combination

temperature - pressure relief valve by the manufacturer.

The valve is certified 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 valve must meet the requirements of local codes,

but not less than a combination temperature and pressure relief

valve certified as indicated in the above paragraph.

The valve must be marked with a maximum set pressure not to

exceed the marked hydrostatic working pressure of the water heater

(150 psi = 1,035 kPa) and a discharge capacity not less than the

water heater input rate as shown on the model rating plate.

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

will not cause any bodily injury or property damage because the

water may be extremely hot.

for safe operation of the water heater, the relief valve must

not be removed from its designated opening nor plugged.

The temperature-pressure relief valve must be installed directly

into the fitting of the water heater designed for the relief valve.

Provide tubing so that any discharge will exit only within 6 inches

(153 mm) above an adequate drain, or external to the building

or structure. 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.

If after manually operating the valve, it fails to completely

reset and continues to release water, immediately close

the cold water inlet to the water heater, follow the draining

instructions, and replace the temperature-pressure relief valve

with a new one.

fillinG the water heater

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

and the tank. Do not connect tubing directly to discharge drain

unless a 6 inch air gap is provided. The relief valve must be allowed

to discharge water in sufﬁcient quantities, should circumstances

demand, to prevent bodily injury, hazard to life, or property damage.

If the discharge pipe is not connected to a drain or other suitable

means, the water ﬂow may cause property damage.

Never use this water heater unless it is completely full of

water. To prevent damage to the tank and heating element,

the tank must be filled with water. Water must flow from

the hot water faucet before turning “ON” electrical supply

to the water heater. The manufacturer will not warrant any

elements damaged by failure to follow instructions.

To fill the water heater with water:

The Discharge Pipe:

1. Open the cold water supply valve to the water heater.

note: the cold water supply valve must be left open

when the water heater is in use.

• Shall not be smaller in size than the outlet pipe size of the valve,

or have any reducing couplings or other restrictions.

2. To ensure complete filling of the tank, allow air to exit

by opening the nearest hot water faucet. Allow water

to run until a constant flow is obtained. This will let air

out of the water heater and the piping.

• 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.

3. Check all water piping and connections for leaks. Repair

as needed.

• Shall terminate at an adequate drain or external to the building

or structure.

4. Never alter or modify the certified construction of the

water heater or its components, or bypass any safety

features. Doing so voids all warranties.

• Shall not have any shut-off valve between the relief valve and

tank nor in the discharge pipe.

wirinG diaGram

fiGure 5.

ꢀ0

wirinG

You must provide all wiring of the proper size outside of the water

heater. You must obey the local codes and the electric company

requirements when you install this wiring.

This water heater is supplied with a flexible, grounded power cord

and connects to a standard three-wire 120 volt 60Hz, grounded

type outlet. If an outlet is not within reach of the power cord,

contact a local electrician/electrical contractor or the local electric

utility to have a properly sized circuit (including outlet, wiring and

breaker) installed. NOTE: Check the water heater’s data plate

for power requirements.

If you are not familiar with the electric codes and practices, or

if you have any doubt, even the slightest doubt, in your ability

to connect the wiring to this water heater, obtain the service of

a competent electrician. Contact a local electrical contractor

and/or the local electric utility.

Never use the water heater unless it is completely full of water.

To prevent damage to the tank and the heating element, the tank

must be filled with water. Water must flow from the hot water

faucet before turning on the power.

WATER HEATERS EQUIPPED FOR ONE VOLTAGE ONLY:

This water heater is equipped for one type voltage only. Check

the rating plate near the bottom access panel for the correct

voltage. DO NOT use this water heater with any voltage other

than the one shown on the model rating plate. Failure to use the

correct voltage can cause problems which can result in DEATH,

SERIOUS BODILY INJURY, OR PROPERTY DAMAGE. If you

have any questions or doubts consult your electric company.

If wiring from your fuse box or circuit breaker box was aluminum

for your old water heater, replace it with copper wire. If you wish

to reuse the existing aluminum wire, have the connection at the

water heater made by a competent electrician. Contact a local

electrical contractor and/or the local electric utility.

ꢀꢀ

temperature reGulation

temperature adjustment

To change the temperature setting:

The white knob on the front of the water heater is the temperature

control. When the “OFF” mark is aligned with the raised indicator

arrow, the water heater is off. Turn the knob clockwise to increase the

temperature, and counterclockwise to decrease the temperature. The

knob is marked with circular indentations of increasing size. The larger

the indentation, the higher the temperature setting. See Figure 6. The

temperature range of this water heater is 68°F at the lowest setting

and 150°F at the maximum setting. This water heater is shipped in the

“OFF” position. Adjust the dial to the desired temperature.

HOTTER WATER CAN SCALD: Water heaters are intended

to produce hot water. Water heated to a temperature

which will satisfy space heating, clothes washing, dish

washing, 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 infirm, or

physically/mentally disabled. If anyone using hot water in

your home fits into one of these groups or if there is a

local code or state law requiring a certain temperature

water at the hot water tap, then you must take special

precautions. In addition to using the lowest possible

temperature setting that satisfies your hot water needs,

a means such as a mixing valve, should be used at

the hot water taps used by these people or at the

water heater. Mixing valves are available from your local

plumbing contractor. Follow manufacturer’s instructions

for installation of the valves. Before changing the factory

setting on the thermostat, see Figure 6.

Never allow small children to use a hot water tap or to draw

their own bath water. Never leave a child or handicapped

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 thermostat be

set for the lowest temperature which satisfies your hot

water needs. This will also provide the most energy

efficient operation of the water heater.

temperature settinGs

It is recommended that the dial be set lower whenever possible.

Temperature

Setting

Time to Produce 2nd & 3rd

Degree Burns on Adult Skin

150°F (66°C)

140°F (60°C)

130°F (54°C)

120°F (49°C)

About 1-1/2 seconds

Less than 5 seconds

About 30 seconds

KEEPING THE THERMOSTAT SETTING AT 120°F (49°C)

OR LOWER WILL REDUCE THE RISK OF SCALDS.

More than 5 minutes

Figure 6 shows the approximate time-to-burn relationship for

normal adult skin.

fiGure 6.

ꢀꢁ

for Your information

“air” in hot water faucets

thermal eXpansion

Water supply systems may, because of such events as high line

pressure, frequent cut-offs, the effects of water hammer among others,

haveinstalleddevicessuchaspressurereducingvalves, checkvalves,

back ﬂow preventers, etc. to control these types of problems. When

these devices are not equipped with an internal by-pass, and no other

measures are taken, the devices cause the water system to be closed.

Aswaterisheated, itexpands(thermalexpansion)andclosedsystems

do not allow for the expansion of heated water.

HYDROGEN GAS: Hydrogen gas can be produced in a hot water

system that has not been used for a long period of time (generally

two weeks or more). Hydrogen gas is extremely ﬂammable and

explosive. To prevent the possibility of injury under these conditions,

we recommend the hot water faucet, located farthest away be opened

for several minutes before any electrical appliances which are

connected to the hot water system are used (such as a dishwasher

or washing machine). If hydrogen gas is present, there will probably

be an unusual sound similar to air escaping through the pipe as the

hot water faucet is opened. There must be no smoking or open

ﬂame near the faucet at the time it is open.

The water within the water heater tank expands as it is heated and

increases the pressure of the water system. If the relieving point of

the water heater’s temperature-pressure relief valve is reached, the

valve will relieve the excess pressure. the temperature-pressure

relief valve is not intended for the constant relief of thermal

expansion. This is an unacceptable condition and must be corrected.

It is recommended that any devices installed which could create a

closed system have a by-pass and/or the system have an expansion

tank or device to relieve the pressure built by thermal expansion in

the water system. Expansion tanks are available for ordering through

a local plumbing contractor. Contact the local water heater supplier

or service agency for assistance in controlling these situations.

hiGh water temperature shut off sYstem

A non-adjustable high temperature limit control operates before

steam temperatures are reached. The high limit switch must be reset

manually when it operates. BECAUSE THE HIGH LIMIT OPERATES

ONLY WHEN ABNORMALLY HIGH WATER TEMPERATURES

ARE PRESENT, IT IS IMPORTANT THAT A QUALIFIED

SERVICE AGENT BE CONTACTED TO DETERMINE

THE REASON FOR OPERATION BEFORE RESETTING.

stranGe sounds

Possible noises due to expansion and contraction of some metal

parts during periods of heat-up and cool-down do not necessarily

represent harmful or dangerous conditions.

operational conditions

water odor

In each water heater there is installed at least one anode rod (see

parts sections) for corrosion protection of the tank. Certain water

conditions will cause a reaction between this rod and the water.

The most common complaint associated with the anode rod is one

of a “rotten egg smell” in the hot water. This odor is derived from

hydrogen sulﬁde gas dissolved in the water. The smell is the result

of four factors which must all be present for the odor to develop:

A. A concentration of sulfate in the supply water.

B. Little or no dissolved oxygen in the water.

C. A sulfate reducing bacteria which has accumulated within the

water heater (this harmless bacteria is nontoxic to humans).

D. An excess of active hydrogen in the tank. This is caused by the

corrosion protective action of the anode.

• Turn off and unplug the water heater. Do not attempt to reset

thermostat with power on.

• Remove the front panel, see “Removing Front Panel” in the

Periodic Maintenance section.

Smelly water may be eliminated or reduced in some water heater

models by replacing the anode(s) with one of less active material,

and then chlorinating the water heater tank and all hot water lines.

Contact the local water heater supplier or service agency for further

informationconcerninganAnodeReplacementKitandthischlorination

treatment. If the smelly water persists after the anode replacement and

chlorinationtreatment, wecanonlysuggestthatchlorinationoraeration

of the water supply be considered to eliminate the water problem.

• Remove the insulation to expose the reset button.

• Reset the high limit by pushing in the red button.

• Replace the insulation so that it completely covers the thermostat

and element.

• Replace the front panel.

do not remove the anode leaving the tank unprotected. By doing

so, all warranty on the water heater tank is voided.

• Plug in and turn on the water heater.

ꢀ3

periodic maintenance

not cause any property damage, as the water may be extremely hot,

see Figure 7.

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

sacriﬁces itself to protect the tank. Instead of corroding the tank, water

ions attack and eat away the anode rod. This does not affect the

water’s taste or color. The rod must be maintained to keep the tank

in operating condition.

fiGure 7.

If after manually operating the valve, it fails to completely reset and

continues to release water, immediately close the cold water inlet

to the water heater, follow the draining instructions, and replace the

temperature-pressure relief valve with a new one.

NOTE: The use of a water softener may decrease the life of the water

heater tank.

If the temperature-pressure relief valve on the appliance weeps

or discharges periodically, this may be due to thermal expansion.

You may have a check valve installed in the water line or a water

meter with a check valve. Consult your local water supplier or

service agency for further information. Do not plug or remove the

temperature-pressure relief valve.

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

qualified technician, and at a minimum should be checked every

three years. The anode rod in this unit is attached to the element

flange. For removal instructions, see “ELEMENT CLEANING /

REPLACEMENT.”

draininG

Typical (but not all) signs of a depleted anode rod are as

follows:

•

The majority of the rods diameter is less than 3/8”

Signiﬁcantsectionsofthesupportwire(approximately1/3ormore

of the anode rod’s length) are visible.

If the anode rod shows signs of either or both it should be replaced.

NOTE: Whether re-installing or replacing the anode rod, check

for any leaks and immediately correct if found.

The water heater should be drained if being shut down during

freezing temperatures. Also periodic draining and cleaning of

sediment from the tank may be necessary.

temperature-pressure relief valve operation

1. Turn off and unplug the water heater from the electrical outlet.

2. CLOSE the cold water inlet valve to the water heater.

3. OPEN a nearby hot water faucet and leave open to allow for

draining.

4. Disconnect water connections. Remove unit from wall. UNIT WILL

BE HEAVY. Turn unit upside down and drain unit into a suitable

drain or receptacle.

removinG the front panel

The temperature-pressure relief valve must be manually operated

at least once a year.

1. Turn off and unplug the water heater from the electrical outlet

and follow “DRAINING INSTRUCTIONS.”

When checking the temperature-pressure relief valve operation, make

sure that (1) no one is in front of or around the outlet of the temperature-

pressure relief valve discharge line, and (2) that the water discharge will

2. Remove the temperature knob by pulling straight out.

ꢀ4

3. Using a Philips screwdriver, unscrew the bottom screw securing

the outer door, see Figure 8.

REPLACEMENT

1. Place the new thermostat against the front panel and secure

it with the two screws.

4. Lift up and remove front panel.

2. Reattach the wires at the spade connections, taking care to

place them in their original locations. Be sure to push the

connector completely onto the spade terminals.

3. Secure the temperature sensor to the tank by tightening the

nuts. Be sure the sensor is ﬁrmly in contact with the tank

surface.

4. Replace the insulation block and the front panel.

element cleaninG / replacement

fiGure 8.

thermostat removal / replacement

To remove the element from the tank in order to clean or replace it:

ꢀ. Turn off and unplug the water heater from the electrical outlet

and follow “DRAINING INSTRUCTIONS.”

2. Remove the front panel, see the “REMOVING THE FRONT

PANEL” section in this manual. Remove the insulation pad.

REMOVAL

3. Remove the two screws from the mounting bracket, see Figure

10, being careful not to drop the screws into the unit, as they will

be difﬁcult to retrieve. Remove bracket and set screws aside.

1. Turn off and unplug the water heater from the electrical outlet.

2. Remove the front panel, see the “REMOVING THE FRONT

PANEL” section in this manual. Remove the insulation pad.

4. Remove the two spade connectors from the element.

3. Using a 7mm wrench, loosen the nuts securing the high limit switch

to the tank enough to rotate the switch 90° counterclockwise and

slide it out from beneath the bracket. It is not necessary to remove

the nuts completely.

5. Using a 10mm wrench, remove the four nuts around the element

ﬂange. Set nuts and lockwashers aside.

6. Lift element up to clear the four mounting bolts, rotate 15° clockwise,

and lift out.

4. Remove the 3 wires (white, brown, and green/yellow) from the

thermostat at the spade connections, carefully taking note of the

original location of each wire.

7. Discard the old gasket and clean the area around the element

opening. Remove any sediment from or around the element opening

and inside the tank.

5. Unscrew the 2 screws securing the thermostat to the front panel

and remove thermostat.

8. If you are cleaning the element you have removed, do so by

scraping or soaking in vinegar or a deliming solution.

note: replacement elements must (1) be the same voltage

and (2) no greater wattage than listed on the model rating plate

afﬁxed to the water heater.

9. A new gasket must be used in all cases to prevent a possible

water leak. Place new element gasket in the element opening

over the four element bolts, orienting the gasket bulge facing

water side.

10.Insert the curved part of the element, rotate 20° clockwise, and

continue to insert the element, being sure that the four bolts ﬁt into

the element ﬂange.

11.Replace the four lockwashers and 10mm nuts. Tighten until snug.

DO NOT OVERTIGHTEN.

fiGure 9.

12.Place unit back on wall mounting bracket hooks. Reconnect the

ꢀ5

water inlet and outlet, open the nearest hot water tap and follow

ﬁlling instructions.

5. Follow instructions for replacing the element in “ELEMENT

CLEANING/REPLACEMENT.”

hiGh limit switch removal and replacement

1. Turn off and unplug the heater from the electrical outlet.

2. Remove the front panel, see the “REMOVING THE FRONT

PANEL” section in this manual. Remove the insulation pad.

Remove personnel barrier.

3. Remove the four wires connected to the switch, taking care

to note the original placement of each wire.

Never use this water heater unless it is completely full of water. To

prevent damage to the tank and heating element, the tank must be

ﬁlled with water. Water must ﬂow from the hot water faucet before

turning “ON” power. The manufacturer will not warrant any elements

damaged by failure to follow instructions.

4. Using a 7mm wrench, remove the nuts securing the high

limit switch to the tank enough to rotate the switch 90°

counterclockwise and slide it out from beneath the bracket.

It is not necessary to remove the nuts completely.

15.Check element for water leaks. If leakage occurs, tighten element.

If necessary drain tank before repeating Steps 7 and 8, remove

element and reposition gasket. Then repeat Steps 10 through 15.

5. Place the new switch beneath the bracket and rotate it 90°

clockwise.

16.Replace the two spade connectors on element into their original

positions.

note: the taller spade terminal will be on the right side.

17.Replace the mounting bracket with the center rise facing outward

and the screw hole up, see Figure 10.

18.Replace the insulation and front panel, lining up the three tabs at

the top with the slots in the casing.

19.Replace the retaining screw and the temperature knob.

20.Plug heater into electrical outlet.

fiGure 11.

6. Replace and tighten the nuts so the high limit switch is firmly

in contact with the tank surface.

7. Replace the four wires, taking care that they are replaced

into their original positions and tighten screws.

8. Replace personnel barrier; replace insulation block and the

front panel.

service

If a condition persists or you are uncertain about the operation

of the water heater contact a service agency.

fiGure 10.

Use this guide to check a “Leaking” water heater. Many

suspected “Leakers” are not leaking tanks. Often the source of

the water can be found and corrected.

TO REMOVE AND REPLACE ANODE:

1. Follow steps 1-8 of the Element Cleaning/Replacement section.

2. Using a 7mm wrench, remove the nut securing the anode.

3. Unscrew and remove anode.

If you are not thoroughly familiar with your water heater and

safety practices, contact a qualified installer to check the water

heater.

4. Screw in the new anode and secure with the retaining nut.

leaKaGe checKpoints

Read this manual ﬁrst. Make sure the electrical power supply has

been turned “OFF” before checking the tank for leakage.

*A. Condensation and dripping may be seen on pipes if the water

temperature is low in humid weather or pipe connections may

be leaking.

B. Small amounts of water from temperature-pressure relief valve

may be due to thermal expansion or high water pressure in your

area. If the valve is not piped to an open drain the released

water could be mistaken for a leaking heater, see “Thermal

Expansion” section.

*C. The temperature-pressure relief valve may be leaking at the

tank ﬁtting.

fiGure 12.

D. Water on the side of the tank may be condensation due to the

panel or insulation not being in place.

*E. Water in the water heater bottom or on the ﬂoor may be from

condensation, loose connections, or the relief valve. DO NOT

replace the water heater until a full inspection of all possible

water sources is made and necessary corrective steps taken.

Leakage from other appliances, water lines, or ground seepage

should also be checked.

To check where threaded portion enters tank, insert cotton

swab between jacket opening and ﬁtting. If cotton is wet, follow

“Draining” instructions in the “Periodic Maintenance” section

and then remove ﬁtting. Put pipe dope or teﬂon tape on the

threads and replace. Then follow “Filling the Water Heater”

instructions in the “Installing the New Water Heater” section.

Key no. part description

ꢀ7

trouBleshootinG Guidelines

These guidelines should be utilized by a qualiﬁed service agent.

problem

possible cause(s)

corrective action

Tighten threaded connections.

Improperly sealed, hot or cold supply connection,

relief valve or drain valve.

water leaKs

(see leakage checkpoints in this manual)

Inspect other appliances near water heater.

Leakage from other appliances or water lines.

No power to heater.

Turn on electrical switch. Check for blown

fuses or tripped breaker.

no hot water

Reset. Check for source of trouble and correct.

Replace thermostat.

High Temperature Limit Switch open.

Non-functioning thermostat.

insufficient hot water

Replace thermostat.

Non-functioning thermostat.

Improper calibration.

Replace thermostat.

Set thermostat to desired temperature.

Drain. Determine if water treatment is needed.

Thermostat set too low.

Sediment or lime in tank.

Install adequate water heater.

Correct piping.

Heater too small for job.

Wrong piping connections.

Leaking faucets.

Repair faucets.

Review and reduce hot water consumption.

Insulate piping.

Wasted hot water.

Long runs of exposed pipe.

Hot water piping on outside wall.

Improper Calibration.

Insulate piping.

Replace thermostat.

hiGh operation costs

Set thermostat to desired setting.

Drain. Flush-Provide water treatment if needed.

Install adequate heater.

Correct piping.

Thermostat set too high.

Sediment or lime in tank.

Heater too small for job.

Wrong piping connections.

Leaking faucets.

Repair faucets.

Review and reduce hot water consumption.

Insulate piping.

Wasted hot water.

Long runs of exposed piping.

Hot water piping in exposed wall.

Non-functioning element.

Excessive water pressure.

Insulate piping.

Replace element.

slow hot water recoverY

drip from relief valve

Use Pressure Reducing Valve and Pressure

Relief Valve.

See “Thermal Expansion” in the For Your Infor-

mation section.

Closed system.

thermostat does not shut off

Replace thermostats.

Non-functioning thermostats.

Improper calibration.

water odor

See “Operational Conditions” in the For Your

Information section.

Sulﬁdes in the water.

water heater sounds

Contact dealer to clean or replace elements.

Scale accumulation on elements.

ꢀ8

repair parts list

Now that you have purchased this water heater, should a need

element Gasket

ever exist for repair parts or service, simply contact the company

it was purchased from or the manufacturer listed on the rating

plate on the water heater.

anode rod

element assembly with Gasket, anode & fasteners

high limit with personnel Barrier

temperature sensor and thermostat

mounting Bracket

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

selling prices will be furnished on request or parts will

be shipped at prevailing prices and you will be billed

accordingly.

5-6

The model number of your Water Heater will be found on the

rating plate located above or adjacent to outer door.

front panel

temperature control Knob

heat traps

WHEN ORDERING REPAIR PARTS, ALWAYS GIVE THE

FOLLOWING INFORMATION:

*13

*15

dip tube

•

MODEL NUMBER

SERIAL NUMBER

VOLTAGE AND ELEMENT WATTAGE

PART DESCRIPTION

temperature-pressure relief valve

element Bolts

personnel Barrier

this is a repair parts list, not a pacKinG list.

manual

* not illustrated.

fiGure 13.

residential electric warrantY

THIS WARRANTY IS APPLICABLE TO THE ORIGINAL

This warranty shall apply only when the heater is:

OWNER ONLY. In accordance with the warranty terms and

conditions speciﬁed below.

•

owned by the original purchaser;

installed for indoor operation only;

used at temperatures not exceeding the maximum

calibrated setting of its thermostat;

used at water pressure not exceeding the working

pressure shown on the heater;

ﬁlled with potable water, free to circulate at all times

and with the tank free of damaging water sediment

or scale deposits;

used in a non-corrosive and non-contaminated

atmosphere;

used with factory approved anode(s) installed;

in its original installation location;

in the United States, its territories or possessions,

and Canada;

sized in accordance with proper sizing techniques

for residential water heaters;

bearing a rating plate which has not been altered,

defaced or removed except as required by the

warrantor;

used in an open system or in a closed system with

a properly sized and installed thermal expansion tank;

connected to the proper voltage or:

A. O. Smith Corporation (the warrantor) will furnish the

ORIGINAL OWNER, 1) a replacement A. O. Smith water

heater of equivalent size and current model if the glasslined

tank in this water heater leaks and, 2) a replacement part

for any component part which fails.

•

THE A. O. SMITH WATER HEATERS REPLACEMENT

MODEL OR PART WILL BE WARRANTED FOR ONLY THE

UNEXPIRED PORTION OF THE ORIGINAL WARRANTY.

The warranty period will be determined by the original date

of purchase of the water heater, or in the absence of a Bill

of Sale verifying said date, from the date of manufacture

indicated on rating plate affixed to this water heater. This

warranty is not transferrable and applies to models listed

below:

•

series

tank

parts

•

promax^®6-Year models

6-year

ECJ,

•

operated at the factory rated input;

installed with no attempted, nor actual modiﬁcation

or alteration of the water heater’s design in any way,

including but not limited to, the attachment of non-

company approved appliances or equipment.

When the water heater has been used for other than single

family residential application;

Any accident to the water heater or any part thereof

(including freezing, ﬁre, ﬂoods, or lightning), any misuse,

abuse or alteration of it, any operation of it in a modiﬁed

form, any operation of the water heater on desalinated

(deionized) water, or any damage caused by attempts

to repair tank leaks or parts, will void this warranty. This

warranty does not cover water heaters replaced for

cosmetic reasons or for reasons of noise, taste, odor,

discolored and/or rusty water. This warranty does not

apply to water heaters used to heat pools, whirlpools or

hot tubs or used for space heating where its sizing does

not conform with speciﬁcations of the heating component

manufacturer.

1. The tank warranty shall be reduced to 1 year for 6 year

models.

2. The parts warranty shall be reduced to 1 year for all

models.

conditions and eXceptions

This warranty shall apply only when the water heater is

installed and operated in accordance with 1) all local ﬁre

codes and plumbing codes, ordinances and regulations,

2) the printed instructions provided with it, 3) good industry

practices, and 4) proper safety practices such as but not

limited to a properly sized drain pan if installed in an area

where leakage from the tank or its connections would result

in damage to the area adjacent to the heater. In addition, a

new temperature and pressure relief valve, certiﬁed by the

Canadian GasAssociation must have been properly installed

and piped to the nearest drain.

This warranty gives you speciﬁc legal rights, and you may

have other rights which vary under the laws of each state. If

any provision of this warranty is prohibited or invalid under

applicable state law, that provision shall be ineffective to

the extent of the prohibition or invalidity

ꢁ0

without invalidating the remainder of the affected provision

or the other provisions of this warranty.

Dealer replacements are made subject to in-warranty

validation by warrantor.

PROOF OF PURCHASEAND PROOF OF INSTALLATION

DATEARE REQUIRED TO SUPPORT WARRANTY CLAIM

FROM ORIGINAL OWNER. THIS FORM DOES NOT

CONSTITUTE PROOF OF PURCHASE OR PROOF OF

INSTALLATION.

service and laBor responsiBilitY

UNDER THIS LIMITED WARRANTY, THE WARRANTOR

WILL PROVIDE ONLY A REPLACEMENT WATER

HEATER OR PART THEREOF. THE OWNER IS

RESPONSIBLE FOR ALL OTHER COSTS. Such costs

may include but are not limited to:

disclaimers

a. Labor charges for service, removal, or reinstallation

of the water heater or part thereof.

NO EXPRESSED WARRANTY HAS BEEN OR WILL BE

MADE IN BEHALF OF THE WARRANTOR WITH

RESPECT TO THE MERCHANTABILITY OF THE

HEATER OR THE INSTALLATION, OPERATION, REPAIR

OR REPLACEMENT OF THE HEATER OR PARTS.

THE WARRANTOR SHALL NOT BE RESPONSIBLE

FOR WATER DAMAGE, LOSS OF USE OF THE UNIT,

INCONVENIENCE, LOSS OR DAMAGE TO PERSONAL

PROPERTY, OR OTHER CONSEQUENTIAL DAMAGE.

THE WARRANTOR SHALL NOT BE LIABLE BY VIRTUE

OF THIS WARRANTY OR OTHERWISE FOR DAMAGE

TO ANY PERSONS OR PROPERTY, WHETHER DIRECT

OR INDIRECT, AND WHETHER ARISING IN CONTRACT

OR IN TORT.

b. Shipping and delivery charges for forwarding the new

water heater or replacement part from the nearest

distributor and returning the claimed defective heater

or part to such distributor.

c. All cost necessary or incidental for handling and

administrative charges, and for any materials and/or

permits required for installation of the replacement

heater or part.

limitation on implied warranties

Implied warranties, including any warranty of

merchantability imposed on the sale of this heater under

state law are limited to one year duration for the heater

or any of its parts. Some states do not allow limitations

on how long an implied warranty lasts, so the above

limitations may not apply to you.

Should governmental regulations or industry standards

prohibit the Manufacturer from furnishing a comparable

model replacement under this warranty, the Owner will

be furnished with the closest comparable water heater

meeting the then current governmental regulations and

industry standards. Asupplementary fee may be assessed

to cover the additional cost associated with the changes

made to meet applicable regulations and standards.

claim procedure

Any claim under this warranty should be initiated with

the dealer who sold the heater, or with any other dealer

handling the warrantor’s products. If this is not practical,

the owner should contact: A.O. Smith Corporation,

500 Tennessee Waltz Parkway, Ashland City, TN 37015.

Phone: 1.800.323.2636 or visit our website: www.

hotwater.com.

important information

Model Number ________________________________

Serial Number ________________________________

installation information

For Canadian customers contact:A.O. Smith Enterprises

LTD., P.O. Box 310, 768 Erie Street, Stratford, Ontario

N5A6T3 or phone: 1.800.265.8520

Date Installed _______________________________

Company’s Name _____________________________

Street or P.O. Box ____________________________

City, State, and Zip Code ________________________

Phone Number________________________________

Plumber’s Name ______________________________

Replacement Parts may be ordered through authorized

servicers or distributors. Refer to your local Yellow Pages

for where to call or contact A.O. Smith Corporation,

500 Tennessee Waltz Parkway, Ashland City, TN 37015.

Phone: 1.800.433.2545 or visit our website at: www.

hotwater.com/parts.

The warrantor will only honor replacement with identical

or similar water heater or parts thereof which are

manufactured or distributed by the warrantor.

www.aosmithwaterheaters.com

ꢁꢀ

notes:

____________________________________________________

ꢁꢁ

notes:

____________________________________________________

ꢁ3

www.aosmithwaterheaters.com

ꢁ4

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