A.O. Smith FCG-75, FCG-100 Installation Manual
Instruction Manual
Low Lead Content
RESIDENTIAL GAS WATER HEATERS
NOT FOR USE IN MANUFACTURED (MOBILE) HOMES
ALL TECHNICAL AND WARRANTY QUESTIONS:
PURCHASED. IF YOU ARE UNSUCCESSFUL, PLEASE WRITE TO THE COMPANY LISTED ON THE RATING PLATE ON THE WATER HEATER.
PRINTED 0315 315628-002
• For Your Safety •
AN ODORANT IS ADDED TO THE GAS USED
BY THIS WATER HEATER.
SHOULD BE DIRECTED TO THE LOCAL DEALER FROM WHOM THE WATER HEATER WAS
KEEP THIS MANUAL IN THE POCKET ON HEATER FOR FUTURE REFERENCE
WHENEVER MAINTENANCE ADJUSTMENT OR SERVICE IS REQUIRED.
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
WARNING
CAUTION
hazardous situation which, if not avoided,
will result in injury or death.
WARNING indicates a potentially hazardous
situation which, if not avoided, could result
in injury or death.
CAUTION indicates a potentially hazardous
situation which, if not avoided, could result in
minor or moderate injury.
CAUTION used without the safety alert
CAUTION
All safety messages will generally tell you about the type of hazard, what can happen if you do not follow the safety message and
how to avoid the risk of injury.
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. This product is certied to comply
with a maximum weighted average of 0.25% lead content as required in some areas.
symbol indicates a potentially hazardous
situation which, if not avoided, could result in
property damage.
IMPORTANT DEFINITIONS
• Qualied Installer: A qualied installer must have ability equivalent to a licensed tradesman in the elds 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 red water heaters. The qualied installer must have a thorough
understanding of this instruction manual.
• Service Agency: A service agency also must have ability equivalent to a licensed tradesman in the elds 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 red 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 which 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.
2
GENERAL SAFETY
3
TABLE OF CONTENTS
SAFE INSTALLATION, USE AND SERVICE............................2
GENERAL SAFETY..................................................................3
TABLE OF CONTENTS ............................................................4
INTRODUCTION ......................................................................4
Preparing for the New Installation .....................................4
TYPICAL INSTALLATION ......................................................5,6
LOCATING THE NEW WATER HEATER ............................. 7-9
Facts to Consider About Location ..................................7,8
Insulation Blankets ............................................................8
Combustion Air and Ventilation for Appliances
Located in Unconned Spaces .........................................8
Combustion Air and Ventilation for Appliances
Located in Conned Spaces ..........................................8,9
INSTALLING THE NEW WATER HEATER ...................... 10-14
Water Piping ..............................................................10,11
Closed Water System .....................................................10
Thermal Expansion .........................................................10
Temperature-Pressure Relief Valve ................................11
Filling the Water Heater ..................................................12
Venting .......................................................................12,13
Gas Piping .................................................................13,14
Sediment Traps ...............................................................14
LIGHTING & OPERATING INSTRUCTIONS ....................15,16
TEMPERATURE REGULATION ............................................17
FOR YOUR INFORMATION ..............................................17,18
Start Up Conditions ....................................................17,18
Draft Hood Operation ...................................................17
Condensation ..........................................................17,18
Smoke/Odor .................................................................18
Thermal Expansion ......................................................18
Strange Sounds ...........................................................18
Operational Conditions ...................................................18
Smelly Water ................................................................18
“Air” in Hot Water Faucets ...........................................18
High Temperature Shut Off System .............................18
PERIODIC MAINTENANCE ............................................. 19-21
Venting System Inspection..............................................19
Burner Inspection ............................................................19
Burner Cleaning ..............................................................19
Housekeeping ............................................................19,20
Anode Rod Inspection.....................................................20
Temperature-Pressure Relief Valve Operation ...............20
Draining and Flushing .....................................................20
Drain Valve Washer Replacement ..................................20
Service ............................................................................21
LEAKAGE CHECKPOINTS ....................................................21
REPAIR PARTS ......................................................................22
TROUBLESHOOTING GUIDELINES .....................................23
WARRANTY ......................................................................Insert
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:
• UL - Underwriters Laboratories Inc.
• ANSI - American National Standards Institute
• NFPA - National Fire Protection Association
• ASME - American Society of Mechanical Engineers
• AHRI - Air-Conditioning, Heating and Refrigeration Institute
• CAN - Canada
• EPACT - Energy Policy Act
• CSA - Canadian Standards Association
This gas-fired water heater is design certified by Underwriters
Laboratories Inc. under American National Standard/CSA Standard
for Gas Water Heaters ANSI Z21.10.3 • CSA 4.3 (current edition).
PREPARING FOR THE INSTALLATION
1. Read the “General Safety” section, page 3 of this manual
rst 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-red 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 rst few pages, READ THE ENTIRE MANUAL BEFORE
ATTEMPTING TO INSTALL OR OPERATE THE WATER HEATER.
2. The installation must conform with these instructions and the local
code authority having jurisdiction. In the absence of local codes,
installations shall comply with the National Fuel Gas Code ANSI
Z223.1/NFPA 54 current addition. This publication is available from
the CSA International, 8501 East Pleasant Valley Rd., Cleveland
Ohio 44131, or The 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 gas 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. Correct combustion, vent action, and vent pipe installation
are very important in preventing death from possible carbon
monoxide poisoning and res. See Figures 3 and 8.
Examine the location to ensure the water heater complies with
the “Locating the New Water Heater” 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 Ofce of the State
Architect, 400 P Street, 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.
4
TYPICAL INSTALLATION
GET TO KNOW YOUR WATER HEATER - GAS MODELS
A Vent Pipe
B Drafthood
C Anode
D Hot Water Outlet
E Outlet
F Insulation
G Gas Supply
H Manual Gas Shut-off Valve
* INSTALL IN ACCORDANCE WITH
LOCAL CODES.
* SEDIMENT TRAP AS REQUIRED
BY LOCAL CODES.
* ALL PIPING MATERIALS TO BE
SUPPLIED BY CUSTOMERS.
I Ground Joint Union
J Sediment Trap
K Inner Door
L Outer door
M Union
N Inlet Water Shut-off Valve
O Cold Water Inlet
P Inlet Dip Tube
Q Temperature-Pressure Relief Valve
R Rating Plate
S Flue Bafe(s)
T Gas Control Valve/Thermostat
U Drain Valve
V Pilot and Main Burner
W Flue
X Metal Drain Pan
(T) GAS CONTROL VALVE/THERMOSTAT
**CLOSED WATER SYSTEMS ARE THOSE
WITH BACK FLOW PREVENTION DEVICES
INSTALLED IN THE WATER SERVICE LINE.
FIGURE 1.
5
(V) PILOT & MAIN BURNER - NATURAL GAS
(V) PILOT & MAIN BURNER - PROPANE GAS
THERMOCOUPLE
PILOT
BURNER
MAIN
BURNER
TYPICAL INSTALLATION
MIXING VALVE USAGE
FIGURE 2.
This water heater has been design certied as complying with
current edition 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 heating.
ANSI Z21.10.3
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 inrm, or physically/mentally handicapped. If
anyone using hot water in your home ts into one of these groups
or if there is a local code 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
satises 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 qualied 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, see
Figures 15 and 16.
6
LOCATING THE NEW WATER HEATER
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 economical
use of the water heater. 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:
1. Select a location indoors as close as practical to the gas vent or
chimney to which the water heater vent is going to be connected,
and as centralized with the water piping system as possible.
2. Selected location must provide adequate clearances for
servicing and proper operation of the water heater.
Keep combustibles such as boxes, magazines, clothes, etc., away
from the water heater area.
Installation of the water heater must be accomplished in such a manner
that if tank or any connections should leak, the ow will not cause
damage to the structure. For this reason, it is not advisable to install
water heater in an attic or upper oor. When such locations cannot be
avoided, a suitable 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”
(51 mm) greater than the water heater dimensions and must be piped
to an adequate drain. The pan must not restrict combustion air ow.
Water heater life depends upon water quality, water pressure and the
environment in which the water heater is installed. Water heaters are
sometimes installed in locations where leakage may result in property
damage, even with the use of a drain pan piped to a drain. However,
unanticipated damage can be reduced or prevented by a leak detector
or water shut-off device used in conjunction with a piped drain pan.
These devices are available from some plumbing supply wholesalers
and retailers, and detect and react to leakage in various ways:
• Sensors mounted in the drain pan that trigger an alarm or turn off
the incoming water to the water heater when leakage is detected.
• Sensors mounted in the drain pan that turn off the water supply
to the entire home when water is detected in the drain pan.
• Water supply shut-off devices that activate based on the water
pressure differential between the cold water and 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.
INSTALLATIONS IN AREAS WHERE FLAMMABLE LIQUIDS
(VAPORS) ARE LIKELY TO BE PRESENT OR STORED (GARAGES,
STORAGE AND UTILITY AREAS, ETC.): Flammable liquids (such as
gasoline, solvents, propane [LP or butane, etc.] and other substances
such as adhesives, etc.) emit ammable vapors which can be ignited by
a gas water heater’s pilot light or main burner. The resulting ashback
and re can cause death or serious burns to anyone in the area, as well
as property damage. If installation in such areas is your only option,
then the installation must be accomplished in a way that the pilot ame
and main burner ame are elevated from the oor at least 18 inches.
While this may reduce the chances of ammable vapors, from a oor
spill being ignited, gasoline and other ammable substances should
never be stored or used in the same room or area containing a gas
water heater or other open ame or spark producing appliance. NOTE:
Flammable vapors may be drawn by air currents from other areas of
the structure to the appliance.
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 water
heater by at least 3” (76.2 mm) in any direction, or if the water heater
is installed in an alcove or closet, the entire oor must be covered by
the panel. Failure to heed this warning may result in a re hazard.
7
Minimum clearances between the water heater and combustible
materials are 0 inch at the sides and rear, 4” (102 mm) at the front,
and 6” (153 mm) from the vent pipe. Clearance from the top of the
jacket is 12” (305 mm) on most models. Note that a lesser dimension
may be allowed on some models, refer to the label attached adjacent
to the gas control valve on the water heater, see Figure 3.
FIGURE 3.
INSULATION BLANKETS
Insulation blankets are available to the general public for external use
on gas water heaters but are not necessary with these products. The
purpose of an insulation blanket is to reduce the standby heat loss
encountered with storage tank heaters. Your water heater meets or
exceeds the EPACT 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 (For identication of components
mentioned below, see Figure 1). Failure to follow these instructions
can restrict the air ow required for proper combustion, potentially
resulting in re, asphyxiation, serious personal injury or death.
A gas water heater cannot operate properly without the correct amount
of air for combustion. Do not install in a conned area such as a closet,
unless you provide air as shown in the “Locating The New Water Heater”
section. Never obstruct the ow of ventilation air. If you have any doubts
or questions at all, call your gas supplier. Failure to provide the proper
amount of combustion air can result in a re or explosion and cause
death, serious bodily injury, or property damage.
FIGURE 4.
If this water heater will be used in beauty shops, barber shops, cleaning
establishments, or self-service laundries with dry cleaning equipment,
it is imperative that the water heater or water heaters be installed so
that combustion and ventilation air be taken from outside these areas.
Propellants of aerosol sprays and volatile compounds, (cleaners,
chlorine based chemicals, refrigerants, etc.) in addition to being highly
ammable in many cases, will also change to corrosive hydrochloric
acid when exposed to the combustion products of the water heater.
The results can be hazardous, and also cause product failure.
• Do not apply insulation to the top of the water heater, as this will
interfere with safe operation of the draft hood.
• Do not cover the outer door, gas control valve/thermostat or
temperature & pressure relief valve.
• Do not allow insulation to come within 2” (50.8 mm) of the oor to
prevent blockage of combustion air ow to the burner.
• 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 manufacturer
for placement on the blanket directly over the existing labels.
• Do inspect the insulation blanket frequently to make certain it
does not sag, thereby obstructing combustion air ow.
COMBUSTION AIR AND VENTILATION FOR
APPLIANCES LOCATED IN UNCONFINED SPACES
UNCONFINED SPACE is space whose volume is not less than
50 cubic feet per 1,000 Btu per hour (4.8 m3 per kW) of the aggregate
input rating of all appliances installed in that space. Rooms
communicating directly with the space in which the appliances are
installed, through openings not furnished with doors, are considered
a part of the unconned space.
In unconned spaces in buildings, inltration may be adequate to provide
air for combustion, ventilation and dilution of ue gases. However, in
buildings of tight construction (for example, weather stripping, heavily
insulated, caulked, vapor barrier, etc.), additional air may need to
be provided using the methods described in “Combustion Air and
Ventilation for Appliances Located in Conned Spaces.”
COMBUSTION AIR AND VENTILATION FOR
APPLIANCES LOCATED IN CONFINED SPACES
CONFINED SPACE is a space whose volume is less than 50 cubic
feet per 1,000 Btu per hour (4.8 m3 per kW) of the aggregate input
rating of all appliances installed in that space.
8
A. ALL AIR FROM INSIDE BUILDINGS: (See Figures 4 and 5)
The conned space shall be provided with two permanent openings
communicating directly with an additional room(s) of sufcient
volume so that the combined volume of all spaces meets the
criteria for an unconned space. The total input of all gas utilization
equipment installed in the combined space shall be considered in
making this determination. Each opening shall have a minimum
free area of one square inch per 1,000 Btu per hour (22 cm
the total input rating of all gas utilization equipment in the conned
space, but not less than 100 square inches (645 cm
2
/kW) of
2
). One opening
shall commence within 12” (30 cm) of the top and one commencing
within 12” (30 cm) of the bottom of the enclosures.
FIGURE 5.
FIGURE 7.
4. When ducts are used, they shall be of the same cross-sectional
area as the free area of the openings to which they connect. The
minimum short side dimension of rectangular air ducts shall not
be less than 3” (76.2 mm), see Figure 8.
5. Alternatively a single permanent opening may be used when
communicating directly with the outdoors, or with spaces that
freely communicate with the outdoors. The opening shall have a
minimum free area of 1 square inch per 3,000 BTU per hour (8.3
cm2/kW) of total input rating of all equipment in enclosure. See
Figure 8A.
B. ALL AIR FROM OUTDOORS: (See Figures 6, 7 and 8)
The confined space shall be provided with two permanent
openings, one commencing within 12” (30 cm) of the top and one
commencing within 12” (30 cm) from the bottom of the enclosure. The
openings shall communicate directly, or by ducts, with the outdoors or
spaces (crawl or attic) that freely communicate with the outdoors.
1. When directly communicating with the outdoors, each opening shall
have a minimum free area of 1 square inch per 4,000 Btu per hour
2
(5.5 cm
/kW) of total input rating of all equipment in the enclosure,
see Figure 6.
FIGURE 8.
6. Louvers and Grilles: In calculating free area, consideration shall be given
to the blocking effect of louvers, grilles or screens protecting openings.
Screens used shall not be smaller than 1/4 inch (6.4 mm) mesh. If the
free area through a design of louver or grille is known, it should be
used in calculating the size opening required to provide the free area
specied. If the design and free area is not known, it may be assumed
that wood louvers will be 20-25 percent free area and metal louvers
and grilles will have 60-75 percent free area. Louvers and grilles shall
be xed in the open position or interlocked with the equipment so that
they are opened automatically during equipment operation.
7. Special Conditions Created by Mechanical Exhausting or Fireplaces:
operation of exhaust fans, ventilation systems, clothes dryers or
replaces may create conditions requiring special attention to avoid
unsatisfactory operation of installed gas utilization equipment.
FIGURE 6.
2. When communicating with the outdoors through vertical ducts,
each opening must have a minimum free area of 1 square inch
per 4,000 Btu per hour (5.5 cm2/kW) of total input rating of all
equipment in the enclosure, see Figure 7.
3. When communicating with the outdoors through horizontal ducts,
each opening shall have a minimum free area of 1 square inch
per 2,000 Btu per hour (11 cm
2
/kW)) of total input rating of all
equipment in the enclosure, see Figure 8.
FIGURE 8A.
9
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