RESIDENTIAL GAS AND ELECTRIC WATER HEATER
Introduction
Terms .................................................. 1
Tools ................................................... 2
Residential Gas Water Heaters
General Information ............................ 3
Operations and Servicing
Control................................................. 6
Burner ................................................. 7
Gas...................................................... 8
Water Flow .......................................... 9
Service .............................................. 10
Multiple Heater Piping ....................... 14
Lint, Dust & Oil Screen.................. 16
Miscellaneous ................................22
RESIDENTIAL GAS AND ELECTRIC SERVICE HANDBOOK INTRODUCTION
This service handbook is designed to aid in servicing and troubleshooting A.O. Smith
Residential Gas and Electric water heaters in the field. No duplication or reproduction of this book
may be made without the express written authorization of the A.O. Smith Water Products
The following text and illustrations will provide you with a step-by-step procedure to verify
proper installation, operation, and troubleshooting procedures. Additional quick reference data is
included to assist you in servicing this product.
A.O. Smith Water Products Company
©2005
SERVICE HANDBOOK
TABLE OF CONTENTS
Page
Residential Electric Water Heaters
Standard Illustrations......................24
Elements......................................26
A-6 Circuit...................................30
A-6 Sequence of Operation............31
A-7 Sequence of Operation.............33
A-7 - wiring - Post 1995............... 34
A-7 - Sequence of Operation ..........35
Unbalanced 3 phase......................37
C2 No Hot Water...........................40
C-2 Grounded Element Check.........41
A-6 Ohms Check - No Hot Water.....42
A-6 No Hot Water Voltage Check.....43
A-6 Lack of Hot Water Voltage Ck....44
A-7 Ohms Test............................47
A-7 Lack of Hot ...........................49
A-7 Grounded Element Test.........50-51
Miscellaneous and Ohms Table.......52
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Technical Training Department
Ashland City, TN