A.O. Smith GDV User manual

Instruction Manual
1212 PART NO. 321348-001
KEEP THIS MANUAL IN THE POCKET ON HEATER FOR FUTURE REFERENCE
WHENEVER MAINTENANCE ADJUSTMENT OR SERVICE IS REQUIRED.
DIRECT VENT GAS MODELS GDV/GDVT
NOT FOR USE IN MANUFACTURED (MOBILE) HOMES
RESIDENTIAL GAS WATER HEATERS
• For Your Safety •
AN ODORANT IS ADDED TO THE GAS USED
BY THIS WATER HEATER.
ALL TECHNICAL AND WARRANTY QUESTIONS: SHOULD BE DIRECTED TO THE LOCAL DEALER FROM WHOM THE WATER
HEATER WAS PURCHASED. IF YOU ARE UNSUCCESSFUL, PLEASE WRITE TO THE COMPANY LISTED ON THE RATING
PLATE ON THE WATER HEATER.
500 Tennessee Waltz Parkway
Ashland City, TN 37015

2
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.
DANGER indicates an imminently hazardous situ-
ation which, if not avoided, will result in injury or
death.
CAUTION Indicates a potentially hazardous situa-
tion which, if not avoided, could result in minor or
moderate injury.
CAUTION used without the safety alert symbol
indicates a potentially hazardous situation which, if
not avoided, could result in property damage.
WARNING Indicates a potentially hazardous situ-
ation which, if not avoided, could result in injury
or death.
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.
CAUTION
CAUTION
WARNING
DANGER
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.
WARNING: This product contains a chemical known to the State of California to cause cancer, birth defects, or
other reproductive harm. This water heater can cause low-level exposure to some of the substances included in
the Act.
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. This product is certified to comply with a maximum weighted average
of 0.25% lead content as required in some areas.
IMPORTANT DEFINITIONS
• Qualified Installer: A qualified installer must have ability equivalent to a licensed tradesman in the fields of plumbing,
air supply, venting and gas supply, including a thorough understanding of the requirements of the National Fuel Gas
Code as it relates to the installation of gas fired water heaters. The qualified installer must also be familiar with the
design features and use of flammable vapor ignition resistant water heaters, and have a thorough understanding of
this instruction manual.
• Service Agency: A service agency also must have ability equivalent to a licensed tradesman in the fields of plumbing, air supply,
venting and gas supply, including a thorough understanding of the requirements of the National Fuel Gas Code as it relates to the
installation of gas fired water heaters. The service agency must also have a thorough understanding of this instruction manual, and
be able to perform repairs strictly in accordance with the service guidelines provided by the manufacturer.
• Gas Supplier: The Natural Gas or Propane Utility or service who supplies gas for utilization by the gas burning
appliances within this application. The gas supplier typically has responsibility for the inspection and code approval of
gas piping up to and including the Natural Gas meter or Propane storage tank of a building. Many gas suppliers also
offer service and inspection of appliances within the building.
SAFE INSTALLATION, USE AND SERVICE

3
GENERAL SAFETY

4
TABLE OF CONTENTS
SAFE INSTALLATION, USE AND SERVICE 2
IMPORTANT DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . 2
GENERAL SAFETY 3
TABLE OF CONTENTS 4
INTRODUCTION 5
Preparing For The Installation . . . . . . . . . . . . . . . . . . . . . . 5
INSTALLATION REQUIREMENTS FOR THE
COMMONWEALTH OF MASSACHUSETTS 6
TYPICAL INSTALLATION 7
Get To Know Your Water Heater. . . . . . . . . . . . . . . . . . . . . 7
Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Mixing Valve Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
LOCATING THE NEW WATER HEATER 9
Facts To Consider About The Location. . . . . . . . . . . . . . . .9
Insulation Blankets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Vent Termination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
INSTALLING THE NEW WATER HEATER 11
Required Ability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Inspect Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Water Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
T&P Valve And Pipe Insulation (If Supplied). . . . . . . . . . . 12
Temperature-Pressure Relief Valve . . . . . . . . . . . . . . . . . 12
Water (Potable) Heating And Space Heating . . . . . . . . . . 13
Closed Water System. . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Gas Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Sediment Traps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Filling The Water Heater. . . . . . . . . . . . . . . . . . . . . . . . . . 15
Venting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
High Altitude Installations . . . . . . . . . . . . . . . . . . . . . . . . . 16
Combustion Air And Ventilation. . . . . . . . . . . . . . . . . . . . . 16
Vent Terminal Clearances. . . . . . . . . . . . . . . . . . . . . . . . . 16
DV Termination Safety Cover . . . . . . . . . . . . . . . . . . . . . .16
Vent Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Locating Clearance Hole For Vent . . . . . . . . . . . . . . . . . . 17
High Rise Vent Arrangement . . . . . . . . . . . . . . . . . . . . . . 17
Standard Vent Arrangement . . . . . . . . . . . . . . . . . . . . . . .18
Vent Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Securing Vent Termination Assembly To The
Exterior Wall.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Uncompressing The Corrugated Tubing. . . . . . . . . . . . . . 18
Vent Restricter Plate. . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Offset Vent Arrangement. . . . . . . . . . . . . . . . . . . . . . . . . . 19
TEMPERATURE REGULATION 21
Temperature Regulation . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Operating The Temperature Control System . . . . . . . . . . 21
FOR YOUR INFORMATION 22
External Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Start Up Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Operational Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
MAINTENANCE 24
Venting System Inspection . . . . . . . . . . . . . . . . . . . . . . . . 24
Pilot And Main Burner. . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Burner Flames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Replacing The Manifold/Burner Assembly . . . . . . . . . . . . 25
Piezoelectric Igniter System . . . . . . . . . . . . . . . . . . . . . . . 25
Testing The Igniter System. . . . . . . . . . . . . . . . . . . . . . . . 25
Removing And Replacing The Gas Control
Valve/Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Removing The Manifold/Burner Assembly . . . . . . . . . . . . 26
Removing The Burner From The
Manifold/Burner Assembly . . . . . . . . . . . . . . . . . . . . . . . . 27
Replacing The Pilot/Thermopile Assembly. . . . . . . . . . . . 27
Temperature & Pressure Relief Valve. . . . . . . . . . . . . . . . 28
Draining. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Cathodic Protection - Anode. . . . . . . . . . . . . . . . . . . . . . . 28
Drain Valve Washer Replacement . . . . . . . . . . . . . . . . . .28
Anode Rod Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . 28
LEAKAGE CHECKPOINTS 30
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
TROUBLESHOOTING GUIDELINES 31
NOTES 33
RESIDENTIAL GAS WARRANTY 34

5
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:
CSA - Canadian Standards Association
ANSI - American National Standards Institute
NFPA - National Fire Protection Association
ASME- American Society of Mechanical Engineers
AHRI - Air Conditioning, Heating and Refrigeration Institute
LLC - Low Lead Content
This gas-fired water heater is design certified by American Na-
tional Standard ANSI Z21.10.1/CSA 4.1 (current edition).
PREPARING FOR THE INSTALLATION
Read the “General Safety” section, page 3 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. This manual contains instructions
for the installation, operation, and maintenance of the gas-
fired 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 every-
thing on the first few pages, READ THE ENTIRE MANUAL
BEFORE ATTEMPTING TO INSTALL OR OPERATE THE
WATER HEATER.
The installation must conform with these instructions and the
local code authority having jurisdiction. In the absence of lo-
cal codes, installations shall comply with the current edition of
the National Fuel Gas Code ANSI Z223.1/NFPA. This publi-
cation is available from the Canadian Standards Association,
8501 East Pleasant Valley Road, Cleveland, OH 44131.
If after reading this manual you have any questions or do
not understand any portion of the instructions, call the local
gas utility or the manufacturer whose name appears on the
rating plate.
Carefully plan the place where you are going to put the water
heater. Correct combustion, vent action, and vent pipe instal-
lation are very important in preventing death from possible
carbon monoxide poisoning and fires, see Figures 1 and 2.
Examine the location to ensure the water heater complies
with the “Locating the New Water Heater” section in this
manual.
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 proce-
dures. Instructions may be obtained from California Office of
the State Architect, 400 P Street, Sacramento, CA 95814.
Massachusetts Code requires this water heater to be in-
stalled in accordance with Massachusetts 248-CMR 2.00:
State Plumbing Code and 248-CMR 5.00. For more informa-
tion see next page.
•
•
•
•
•
•
1.
2.
3.
4.
5.
6.
INTRODUCTION

6
INSTALLATION REQUIREMENTS FOR THE COMMONWEALTH OF MASSACHUSETTS
For all side wall terminated, horizontally vented power vent, direct vent, and power direct vent gas fueled water heaters installed
in every dwelling, building or structure used in whole or in part for residential purposes, including those owned or operated by the
Commonwealth and where the side wall exhaust vent termination is less than seven (7) feet above finished grade in the area of
the venting, including but not limited to decks and porches, the following requirements shall be satisfied:
INSTALLATION OF CARBON MONOXIDE DETECTORS At the time of installation of the side wall horizontal vented gas fueled
equipment, the installing plumber or gasfitter shall observe that a hard wired carbon monoxide detector with an alarm and battery
back-up is installed on the floor level where the gas equipment is to be installed. In addition, the installing plumber or gasfitter
shall observe that a battery operated or hard wired carbon monoxide detector with an alarm is installed on each additional level
of the dwelling, building or structure served by the sidewall horizontal vented gas fueled equipment. It shall be the responsibility
of the property owner to secure the services of qualified licensed professionals for the installation of hard wired carbon monoxide
detectors.
In the event that the side wall horizontally vented gas fueled equipment is installed in a crawl space or an attic, the hard wired
carbon monoxide detector with alarm and battery back-up may be installed on the next adjacent floor level. In the event that the
requirements of this subdivision can not be met at the time of completion of installation, the owner shall have a period of thirty
(30) days to comply with the above requirements provided that during said thirty (30) day period, a battery operated carbon
monoxide detector with an alarm shall be installed.
APPROVED CARBON MONOXIDE DETECTORS Each carbon monoxide detector as required in accordance with the above
provisions shall comply with NFPA 720 and be ANSI/UL 2034 listed and CSA certified.
SIGNAGE A metal or plastic identification plate shall be permanently mounted to the exterior of the building at a minimum height
of eight (8) feet above grade directly in line with the exhaust vent terminal for the horizontally vented gas fueled heating appliance
or equipment. The sign shall read, in print size no less than one-half (1/2) inch in size, “GAS VENT DIRECTLY BELOW.
KEEP CLEAR OF ALL OBSTRUCTIONS.”
INSPECTION The state or local gas inspector of the side wall horizontally vented gas fueled equipment shall not approve the
installation unless, upon inspection, the inspector observes carbon monoxide detectors and signage installed in accordance with
the provisions of 248 CMR 5.08(2)(a) 1 through 4.
EXEMPTIONS: The following equipment is exempt from 248 CMR 5.08(2)(a)1 through 4:
1. The equipment listed in Chapter 10 entitled “Equipment Not Required To Be Vented” in the most current edition of NFPA 54
as adopted by the Board; and
2. Product Approved side wall horizontally vented gas fueled equipment installed in a room or structure separate from the dwell-
ing, building, or structure used in whole or in part for residential purposes.
MANUFACTURER REQUIREMENTS - GAS EQUIPMENT VENTING SYSTEM PROVIDED When the manufacturer of Product
Approved side wall horizontally vented gas equipment provides a venting system design or venting system components with
the equipment, the instructions provided by the manufacturer for installation of the equipment and the venting system shall
include:
1. Detailed instructions for the installation of the venting system design or the venting system components; and
2. A complete parts list for the venting system design or venting system.
MANUFACTURER REQUIREMENTS - GAS EQUIPMENT VENTING SYSTEM NOT PROVIDED When the manufacturer of a
Product Approved side wall horizontally vented gas fueled equipment does not provide the parts for venting the flue gases, but
identifies “special venting systems,” the following requirements shall be satisfied by the manufacturer:
1. The referenced “special venting system” instructions shall be included with the appliance or equipment installation instruc-
tions; and
2. The “special venting systems” shall be Product Approved by the Board, and the instructions for that system shall include a
parts list and detailed installation instructions.
A copy of all installation instructions for all Product Approved side wall horizontally vented gas fueled equipment, all venting
instructions, all parts lists for venting instructions, and/or all venting design instructions shall remain with the appliance or equip-
ment at the completion of the installation.that the discharge pipe be terminated at an adequate drain inside the building.

7
GET TO KNOW YOUR WATER HEATER REPLACEMENT PARTS
Replacement parts may be ordered through authorized servicers
or distributors. When ordering parts, provide complete model
and serial numbers (see rating plate), quantity and name of part
desired (as listed in Figure 1). Standard hardware items may be
purchased locally.
ALL PIPING MATERIALS TO BE
SUPPLIED BY CUSTOMER. FIGURE 1
VACUUM RELIEF
VALVE
INSTALL PER
LOCAL CODES.
THERMAL
EXPANSION TANK
INSTALLTHERMALEXPANSION
TANK IF WATER HEATER IS
INSTALLED IN A CLOSED
SYSTEM.
List of status codes are shown
at top of gas control valve/thermostat.
FLUE BAFFLE
GAS SUPPLY
LINE
MAIN MANUAL
GAS SHUTOFF
VALVE
GROUND-JOINT
UNION
SEDIMENT
TRAP (DIRT
LEG)
ANODE
HOT WATER
OUTLET PIPE
UNION
INLET DIP
TUBE
TEMPERATURE
AND PRESSURE
RELIEF VALVE
DISCHARGE PIPE
(DO NOT CAP OR
PLUG)
GAS CONTROL
VALVE/
THERMOSTAT
DRAIN VALVE
METAL
DRAIN PAN
FLOOR DRAIN
OUTER DOOR
INLET VALVE
COLD WATER
INLET PIPE
TRIM PLATE
(OUTSIDE)
TRIM PLATE
(INSIDE)
6” MAXIMUM
AIR GAP
TYPICAL INSTALLATION
PILOT
TUBE THERMOPILE
CONNECTOR PILOT / THERMOPILE
ASSEMBLY SCREW
RETAINER
CLIP
WHITE
WIRE
MANIFOLD
COMPONENT
BLOCK
MANIFOLD
DOOR
BURNER AND OTHER
FITTINGS NOT SHOW
FOR CLARITY.
IGNITER
WIRE

8
FIGURE 2
MIXING VALVE USAGE
This water heater has been design certified as complying with
American National Standard/CSA Standard for water heaters
and is considered suitable for:
Water (Potable) Heating and Space Heating: All models are
considered suitable for water (potable) heating and space heat-
ing.
HOTTER WATER CAN SCALD:
Water heaters are intended to produce hot water. Water heated
to a temperature which will satisfy space heating, clothes wash-
ing, 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
handicapped. If anyone using hot water in your home fits into
one of these groups or if there is a local code or state law requir-
ing 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 at plumbing supply or hardware stores.
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.
DRAIN VALVE
TEMPERED POTABLE WATER
TEMPERATURE-PRESSURE
RELIEF VALVE
TO SUITABLE DRAIN
NON-TEMPERED WATER RETURN
COLD WATER INLET
DISCHARGE PIPE
(DO NOT CAP
OR PLUG)
METAL
DRAIN PAN
GAS SUPPLY
NON-TEMPERED WATER SUPPLY
SUGGESTED PIPING
ARRANGEMENT FOR
TOP CONNECTIONS
SHUT-OFF VALVE
MIXING VALVE
6” MAXIMUM
AIR GAP
CERTAIN MODELS ARE EQUIPPED WITH
SIDE PLUMBING CONNECTIONS FOR
SPACE HEATING.

9
FACTS TO CONSIDER ABOUT THE LOCATION
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 eco-
nomical use of the appliance. This water heater is not for use in
manufactured (mobile) homes or outdoor installation.
Whether replacing an old water heater or putting the water heater
in a new location, the following critical points must be observed:
Select a location indoors as close as practical to the vent
terminal or location to which the water heater vent piping is
going to be connected, and as centralized with the water pip-
ing system as possible.
Selected location must provide adequate clearances for ser-
vicing and proper operation of the water heater.
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 metal drain pan
should be installed under the water heater. Metal drain pans are
available at your local hardware store. Such a metal drain pan
must have a minimum length and width of at least 2 in. greater
that the water heater dimensions, a maximum height of 1.75 in.
and must be piped to an adequate drain.
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 metal 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 metal drain pan. These devices
are available from some plumbing supply wholesalers and retail-
ers, and detect and react to leakage in various ways:
Sensors mounted in the metal drain pan that trigger an alarm
or turn off the incoming water to the water heater when leak-
age is detected.
1.
2.
•
Sensors mounted in the metal drain pan that turn off the wa-
ter supply to the entire home when water is detected in the
metal drain pan.
Water supply shut-off devices that activate based on the wa-
ter pressure differential between the cold water and hot 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.
Also, the water heater must be located and/or protected so it is
not subject to physical damage by a moving vehicle.
This water heater must not be installed directly on carpeting.
Carpeting must be protected by metal or wood panel beneath
the water heater extending beyond the full width and depth of
the water heater by at least 3 in. in any direction, or if the water
heater is installed in an alcove or closet, the entire floor must be
covered by the panel. Failure to heed this warning may result in
a fire hazard.
•
•
•
LOCATING THE NEW WATER HEATER

10
INSULATION BLANKETS
Insulation blankets available to the general public for external
use on gas water heaters are not necessary with this product.
The purpose of an insulation blanket is to reduce the standby
heat loss encountered with storage tank water heaters. Your Wa-
ter heater meets or exceeds the NationalAppliance Energy Con-
servation Act 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 (See Figure 1 for identifica-
tion of components mentioned below). Failure to follow these
instructions can result in fire, asphyxiation, serious personal
injury or death.
Do not cover the outer door, thermostat or temperature &
pressure relief valve.
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 from the manu-
facturer for placement on the blanket directly over the exist-
ing labels.
•
•
•
VENT TERMINATION
Before installing water heater determine placement of vent ter-
mination.
Make certain to observe vent location limitations, see Figures 3
& 15.
Minimum clearances between the water heater and combustible
and noncombustible construction are: 0 in. from sides, 0 in. from
back, 4 in. from front of jacket to closet door and 20 in.* from top
of jacket to combustible and noncombustible material. Minimum
vent clearance: 1 in.**. Provide 3 ft. front clearance for servicing
and adequate clearance between the jacket top & ceiling for
servicing the flue vent area, see Figure 3.
* This clearance (20 in.) is required only to accomodate the
minimum vent radius.
** Where the wall is combustible and the wall thickness is over
14 in., 1 in. clearance to combustible surfaces around the vent
terminal is needed. The first 14 in. is zero clearance.
Make certain the vent locations comply with the current edition
of the National Fuel Gas Code ANSI Z223.1/NFPA 54 and/or lo-
cal codes. There is some important information shown in Figure
15.
For a second or more direct vent unit, the distance between vent
terminals must be a minimum of 12 in..
FIGURE 3