A. O. Smith PHXT-52 Installation Manual

Instruction Manual

RESIDENTIAL ELECTRIC

WATER HEATERS

FOR POTABLE WATER

HEATING ONLY

NOT SUITABLE FOR

SPACE HEATING

LISTED

GAMA certification applies to all
residential electric water heaters
with capacities of 20 to 120 gallons.
Input rating of 12 Kw or less.

ALL TECHNICAL AND W ARRANTY QUESTIONS: SHOULD BE DIRECTED TO THE LOCAL DEALER FROM WHOM THE WA TER HEA TER WAS
PURCHASED. IF YOU ARE UNSUCCESSFUL, PLEASE WRITE TO THE COMPANY LISTED ON THE RATING PLA TE ON THE WA TER HEA TER.

KEEP THIS MANUAL IN THE POCKET ON HEA TER FOR FUTURE REFERENCE

WHEN EVER MAINTENANCE ADJUSTMENT OR SERVICE IS REQUIRED.

PRINTED IN THE U.S.A 0805 PART NO. 184639-001

1

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.

DANGER indicates an imminently

DANGER

W ARNING

CAUTION

hazardous situation which, if not avoided,
could 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, may 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

• 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.

2

GENERAL SAFETY

TABLE OF CONTENTS

SAFE INSTALLA TION, USE AND SERVICE ..............................2

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

TABLE OF CONTENTS..............................................................3

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

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

NOTES ......................................................................................4

TYPICAL INST ALLA TION ..........................................................5

WIRING DIAGRAMS .................................................................. 6

MIXING V ALVE USAGE ............................................................ 7

LOCA TING THE NEW WA TER HEA TER..................................... 8

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

Insulation Blankets ...........................................................8

INST ALLING THE NEW WA TER HEATER .................................. 8

Water Piping ................................................................. 8-9

T emperature-Pressure Relief V alve........................... 9-10

Filling the Water Heater.................................................. 10

T&P V alve and Pipe Insulation (Selected Models)......... 10

TEMPERA TURE REGULATION ................................................ 11

T emperature Adjustment................................................ 11

FOR YOUR INFORMATION ..................................................... 12

Thermal Expansion......................................................... 12

Strange Sounds ............................................................. 12

Operational Conditions................................................... 12

Smelly Water .................................................................. 12

“Air” in Hot Water Faucets.............................................12

High Water Temperature Shut Off System .................... 12

PERIODIC MAINTENANCE ....................................................... 12

Anode Rod Inspection.............................................. 12-13

T emperature-Pressure Relief Valve Operation ........... ...13

Draining ..........................................................................13

Drain Valve W asher Replacement .................................13

Service ........................................................................... 13

LEAKAGE CHECKPOINTS ......................................................14

REPAIR P ARTS LIST ...............................................................15

TROUBLESHOOTING .............................................................. 16

WARRANTY ..................................................................... 17-18

3

INTRODUCTION

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 S tandards Institute

• ASME - American Society of Mechanical Engineers

• GAMA - Gas Appliance Manufacturer’s Association

• NEC - National Electric Code

• NFPA - National Fire Protection Association

• UL - Underwriters Laboratory

PREP ARING FOR THE INSTALLA TION

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 BODIL Y 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 . Since we cannot put everything
on the first few pages, READ THE ENTIRE MANUAL BEFORE

ATTEMPTING T O INST ALL OR OPERATE THE W ATER HEA TER.

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 code requirements follow NFPA-70
(latest edition). The National Electric Code which may be ordered
from: National Fire Protection Association, 1 Batterymarch Park,
Quincy, MA 02269.

3. If after reading this manual you have any questions or do not
understand any portion of the instructions, call the local utility or the
manufacturer whose name appears on the rating plate.

4. Carefully plan the place where you are going to put the water heater.
INSTALLA TION OR SER VICE OF THIS WA TER HEA TER REQUIRES
ABILITY EQUIVALENT TO THAT OF A LICENSED TRADESMAN IN
THE FIELD INVOLVED. PLUMBING AND ELECTRICAL WORK ARE
REQUIRED.

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 St ate Architect, 400 P S treet,
Sacramento, CA 95814.

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.

NOTES

4

TYPICAL INSTALLATION

LOWBOYS

UPRIGHTS

INSTA LL SUIT ABLE D RAIN PANS UNDER HEA TERS
TO PREVENT DAMAGE DUE TO LEAKAGE. REFER
TO WATER HEATER LOCATION ON P AGE 8.

COMP ACTS

T ABLE TOPS

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

INSTAL L THERMAL EXP ANSION T ANK OR DEVICE
IF WATER HEATER IS INSTALLED IN A CLOSED
WA TER SYSTEM.

FIGURE 1.

5

WIRING DIAGRAMS

TURN OFF THE HEA TER ELECTRICAL SUPPL Y BEFORE SERVICING ANY ELECTRICAL COMPONENTS.

S-1

THREE WIRE CIRCUIT FOR

ELECTRIC CO. CO-OP

PROGRAMS

C-2

TWO WIRE CIRCUIT FOR SINGLE

ELEMENT HEA TERS EQUIPPED

WITH HIGH LIMIT CONTROL

A-6

TWO WIRE CIRCUIT FOR
NON-SIMUL TANEOUS OPERA TION,
HAS SINGLE HIGH LIMIT CONTROL

A-9

240 VOL T “OFF PEAK” NON-SIMULT ANEOUS

OPERATION BOTT OM ELEMENT ON SEPARA TE

TIME CLOCK OR “OFF PEAK” METER

FIGURE 2.

6