AO Smith 65403072 Residential Gas Water Heater User Guide
- June 16, 2024
- AO Smith
Table of Contents
- AO Smith 65403072 Residential Gas Water Heater
- Specifications
- Product Usage Instructions
- Installation
- Operation
- Maintenance
- FAQs
- COMPLETED INSTALLATION (TYPICAL)
- Fire Risk
- GETTING STARTED
- Venting
- INSTALLATION
- OPERATION
- TROUBLESHOOTING
- MAINTENANCE
- References
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)
AO Smith 65403072 Residential Gas Water Heater
Specifications
- Product Type: Residential Gas Water Heater
- Safety System: Flammable Vapor Ignition Resistant (FVIR)
- Ultra Low Nox Gas Water Heater
- Model Number: 100366637_2000622613_REV. A
- Installation Date: February 2023
Product Usage Instructions
Getting Started
- Before installation, carefully read this manual and the labels on the water heater.
- Ensure that you have the necessary tools and materials for installation.
- If you are unsure about any aspect of the installation, operation, or service, seek professional assistance.
Installation
- Refer to the “COMPLETED INSTALLATION (TYPICAL)” diagram for a visual representation of the installation process.
- Install the vent pipe (A) and draft hood (B) according to local codes.
- Connect the gas supply piping (F) to the gas control valve (S) using a manual gas shut-off valve (G).
- Install the inlet water shut-off valve (M) and cold water inlet (N).
- Ensure that all required components, such as the anode (C), insulation (E), and temperature-pressure relief valve (P), are properly installed.
- Follow local codes for the installation of a drip leg (I) and thermal expansion tank if applicable
Operation
- Familiarize yourself with the various components of the water heater, such as the gas control valve/thermostat (S), drain valve (T), and pilot/main burner (U).
- Use the gas control/temperature knob to adjust the water temperature as desired.
- The status light on the gas control valve will indicate the heating status of the water heater.
- If any issues or malfunctions occur, refer to the troubleshooting section of the manual.
Maintenance
- Regularly inspect the water heater for any signs of wear or damage.
- Follow the maintenance schedule provided in the manual for tasks such as flushing sediment and checking the anode rod.
- If maintenance or service is required, refer to the appropriate sections of the manual for instructions.
Repair Parts
In the event that repair parts are needed, refer to the repair parts section
(page 37) for a list of available parts and their corresponding part numbers.
Notes
- Keep this manual in the pocket on the water heater for future reference.
- Retain your original receipt as proof of purchase.
FAQs
Q: Can I install this water heater myself?
A: While it is possible to install the water heater yourself, it is
recommended to seek professional assistance if you have any doubts or
difficulties following the installation instructions.
Q: How do I adjust the water temperature?
A: You can adjust the water temperature by using the gas control/temperature
knob located on the gas control valve.
Q: What should I do if the water heater malfunctions?
A: If any issues or malfunctions occur, refer to the troubleshooting
section of the manual for guidance on identifying and resolving common
problems.
Q: How often should I perform maintenance on the water heater?
A: Regular maintenance is important to ensure the proper functioning of the
water heater. Refer to the maintenance section of the manual for a recommended
maintenance schedule.
Q: Where can I find replacement parts for the water heater?
A: The repair parts section of the manual provides a list of available parts
and their corresponding part numbers. You can refer to this section to find
the necessary replacement parts.
Installation Instructions and Use & Care Guide
Residential Gas Water Heater
Residential Atmospheric Ultra Low Nox Gas Water Heater with the Flammable
Vapor Ignition Resistant (FVIR) Safety System
DO NOT RETURN THIS UNIT TO THE STORE
Read this manual and the labels on the water heater before you install,
operate, or service it. If you have difficulty following the directions, or
aren’t sure you can safely and properly do any of this work yourself:
Call our Technical Assistance Hotline at
1-877-817-6750 or visit http://
www.AOSmithAtLowes.com. We can help you with installation, operations,
troubleshooting, or maintenance. Before you call, write down the model and
serial number from the water heater’s data plate. Incorrect installation,
operation, or service can damage the water heater, your house and other
property, and present risks including fire, scalding, electric shock, and
explosion, causing serious injury or death.
WARNING: If the information in these instructions is not followed exactly, a fire or explosion may result causing property damage, personal injury or death. Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance. WHAT TO DO IF YOU SMELL GAS · Do not try to light any appliance. · Do not touch any electrical switch; do not use any phone in your building. · Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions. · If you cannot reach your gas supplier, call the fire department. Installation and service must be performed by a qualified installer, service agency or the gas supplier.
LOW LEAD CONTENT
Keep this manual in the pocket on heater for future reference whenever
maintenance, adjustment or service is required. Retain your original receipt
as proof of purchase.
100366637_ 2000622613_REV. A February 2023
COMPLETED INSTALLATION (TYPICAL)
A Vent Pipe B Draft Hood C Anode (Not Shown) D Hot Water Outlet E Insulation F Gas Supply Piping G Manual Gas Shut-off Valve H Ground Joint Union I Drip Leg (Sediment Trap)
J Inner Door
K Outer Door
L Union M Inlet Water Shut-off Valve N Cold Water Inlet
O Inlet Dip Tube P Temperature-Pressure Relief Valve Q Rating Plate R Flue
Baffle
- INSTALL IN ACCORDANCE WITH LOCAL CODES.
- DRIP LEG AS REQUIRED BY LOCAL CODES
- DAMPER ORIENTATION MAY VARY
TO VENT TERMINATION ON
ROOF
S Gas Control Valve/Thermostat T Drain Valve U Pilot and Main Burner V Flue W Metal Drain Pan X Igniter Wire Y Base-Ring Filter Z Flammable Vapor (FV) Sensor AA LDO Module BB Flue Damper
D
F G
H
A B
INSTALL THERMAL EXPANSION TANK IF WATER HEATER IS INSTALLED IN A CLOSED WATER SYSTEM
BB
M
L
N
R
E
V
O
VACUUM RELIEF
VALVE
*INSTALL PER
LOCAL CODES
P
Q
(S) GAS CONTROL VALVE/ THERMOSTAT
A
STATUS ON OFF
B C VEHRYOT
HOT
STATUS LIGHT
·
·
LOW
VAC
GAS CONTROL/TEMPERATURE KNOB
(U) MANIFOLD/BURNER ASSEMBLY IGNITER WIRE
MANIFOLD TUBE
MAIN BURNER
PILOT ASSEMBLY MANIFOLD DOOR
AA S
DISCHARGE PIPE (DO NOT CAP OR PLUG.)
T
I
WZ
JY
K
- ALL PIPING MATERIALS TO BE SUPPLIED BY CUSTOMERS.
NOTE: POWER CORD NOT SHOWN.
IMPORTANT SAFETY INFORMATION
SAFETY
Read and follow all safety messages and instructions in this manual.
This is the safety alert symbol. It is used to alert you to potential physical
injury hazards. Obey all safety messages that follow this symbol to avoid
possible property damage, serious injury or death. Do not remove any permanent
instructions, labels, or the data plate from either the outside of the water
heater or on the inside of the access panels. Keep this manual near the water
heater.
DANGER WARNING CAUTION NOTICE
DANGER indicates hazardous situation that, if not avoided, will result in
death or serious injury.
WARNING indicates a hazardous situation that, if not avoided, could
result in death or serious injury.
CAUTION indicates a hazardous situation that, if not avoided, could
result in minor or moderate injury.
NOTICE indicates practices not related to physical injury.
WARNING! If the information in these instructions is not followed exactly, a
fire or explosion may result causing property damage, personal injury or
death. Do not store or use gasoline or other flammable vapors and liquids in
the vicinity of this or any other appliance.
An odorant is added by the gas supplier to the gas used by this water heater.
This odorant may fade over an extended period of time. Do not depend upon this
odorant as an indication of leaking gas. We recommend installing a fuel gas
and carbon monoxide detector.
This product is certified to comply with a maximum weighted average of 0.25%
lead content as required in some areas.
Important information to keep
Fill out this section and keep this manual in the pocket of the water heater
for reference. Date Installed:
Model number:
Serial number:
Maintenance performed: Date:
Drain and flush tank and remove and inspect anode rod after first six months of operation and at least annually thereafter. Operate the Temperature and Pressure Relief Valve (T&P) annually and inspect T&P valve every 2-4 years (see the label on the T&P valve for maintenance schedule). See the Maintenance section for more information about maintaining this water heater.
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 3
SAFETY
IMPORTANT SAFETY INFORMATION
T o reduce the risk of property damage, serious injury or death, read and
follow the precautions below, all labels on the water heater, and the safety
messages and instructions throughout this manual.
RISKS DURING INSTALLATION AND MAINTENANCE
Lifting Risk
WARNING! The water heater is heavy. Follow these precautions to reduce the
risk of property damage, injuries from lifting or impact injuries from
dropping the water heater.
· Use at least two people to lift the water heater.
· Be sure you both have a good grip before lifting.
· Use an appliance dolly or hand truck to move the water heater.
Explosion Risk
WARNING! Read the water heater’s data plate to determine the type of gas
required. Failure to follow these instructions can result in serious injury or
death from explosion, fire or carbon monoxide poisoning.
· Do not connect a natural gas water heater to an L.P. gas supply.
· Do not connect an L.P. gas water heater to a natural gas supply.
· Use a new CSA approved gas supply line.
· Install a shut-off valve on the gas supply line.
Gas Pressure WARNING! The gas supply pressure
must not exceed the maximum supply pressure as stated on the water heater’s
data plate. The minimum supply pressure is for the purpose of input
adjustment.
RISKS DURING OPERATION
Scalding Risk
This water heater
can make water hot enough to cause severe burns instantly, resulting in severe
injury or death.
· Feel water before bathing or showering.
· To reduce the risk of scalding, install Thermostatic Mixing Valves
(temperature limiting valves) at each point-of-use. These valves automatically
mix hot and cold water to limit the temperature at the tap. Mixing valves are
available from Lowe’s®. Follow manufacturer’s instructions for installation
and adjustment of the valves.
· The gas control valve on this water heater has been factory set to its
lowest setting to reduce the risk of scalding. Higher temperatures increase
the risk of scalding, but even at 120°F, hot water can scald. If you choose a
higher temperature setting, Thermostatic Mixing Valves located at each point-
of-use are particularly important to help avoid scalding.
Table 1
Temperature 120°F (49°C)
Time to Produce a Serious Burn
More than 5 minutes
125°F (52°C)
1½ to 2 minutes
130°F (54°C)
About 30 seconds
135°F (57°C)
About 10 seconds
140°F (60°C)
Less than 5 seconds
145°F (63°C)
Less than 3 seconds
150°F (66°C)
About 1½ seconds
155°F (68°C)
About 1 second
For information about changing the factory temperature setting, refer to the
“Adjusting the Temperature” section in this manual .
Even if you set the water heater’s gas control valve to a low setting, higher
water temperatures may occur in cer-
tain circumstances:
· In some cases, repeated small draws
of water can cause the hot and cold water in the tank to “stack” in layers. If
this happens, the water can be as much as thirty degrees hotter than the gas
control valve setting. This temperature variation is the result of your usage
pattern and is not a malfunction. · Water temperature will be hotter if
someone adjusted the gas control valve to a higher setting. · Problems with
the gas control valve or other malfunctions may result in higher than expected
water temperatures.
· If the water heater is in a hot envi-
ronment, the water in the tank can become as hot as the surrounding air,
regardless of the temperature setting.
4 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
SAFETY
IMPORTANT SAFETY INFORMATION
· If the water supplied to the water heater is pre-heated (for example, by a
solar system) the temperature in the tank may be higher than the water
heater’s temperature setting.
· Should overheating occur or the burner fail to shut off, turn off the manual
gas supply valve to the water heater and call a qualified person.
To reduce the risk of unusually hot water reaching the fixtures in the house,
install Thermostatic Mixing Valves at each point-of-use.
If anyone in your home is at particular risk of scalding (for example, the
elderly, children, or people with disabilities) or if there is a local code or
state law requiring a certain water temperature at the hot water tap, these
precautions are particularly important.
According to a national standard (ASSE 1070) and many local plumbing codes,
the water heater’s gas control valve should not be used as the sole means to
regulate water temperature and avoid scalds.
Properly adjusted Thermostatic Mixing Valves installed at each point-of-use
allow you to set the tank temperature to a higher setting without increasing
risk of scalds. A higher temperature setting allows the tank to provide much
more hot water and can help provide proper water temperatures for appliances
such as dishwashers and washing machines. Higher tank temperatures (140°F)
also kill bacteria that cause a condition known as “smelly water” and can
reduce the levels of bacteria that cause water-borne diseases.
Water Contamination Risk
Do not use chemicals that could contaminate the potable water supply. Do not
use piping that has been treated
with chromates, boiler seal, or other chemicals.
Fire Risk
This water heater is equipped with a Flammable Vapor (FV) sensor which is
designed to detect the presence of flammable vapors. When the sensor detects
those vapors, the unit will shut down and not operate. Even though this water
heater is flammable vapors ignition resistent and is designed to reduce the
chances of flammable vapors being ignited, flammable substances such as
gasoline should never be used or stored in the same area containing a gas
water heater or other open flame or sparkproducing appliance.
Turn the gas control valve OFF and do not operate this appliance if you
suspect flammable vapors have accumulated inside or outside the appliance.
Immediately call a qualified person to inspect the appliance. Water heaters
subjected to a flammable vapors incident will show a discoloration on the
flame arrestor and require replacement of the entire water heater. Improper
installation or an inadequate air supply can also cause the FVIR system to
disable the water heater.
To reduce the risk of a fire that could destroy your home and seriously injure
or kill people:
· Do not store things that can burn easily such as paper or clothes next to
the water heater.
· Do not store or use gasoline or other flammable substances in the vicinity
of this or any other appliance.
· Keep the water heater from becom-
ing wet. Immediately shut the water heater off and have it inspected by a
qualified person if you find that the wiring, thermostat(s) or surrounding
insulation have been exposed to water in any way (e.g., leaks from plumbing,
leaks from the water heater itself can damage property and could cause a fire
risk). If the water heater is subjected to flood conditions or the
thermostat(s) have been submerged in water, the entire water heater must be
replaced.
· Replace the water heater’s viewport if glass is missing or damaged. Repair
the combustion chamber door seals if damaged.
Explosion Risk
High temperatures and pressures in the water heater tank can cause an
explosion resulting in property damage, serious injury or death. A new
Temperature and Pressure (T&P) Relief Valve is included with your water heater
to reduce risk of explosion by discharging hot water. Additional temperature
and pressure protective equipment may be required by local codes.
A nationally recognized testing laboratory maintains periodic inspection of
the valve production process and certifies that it meets the requirements for
Relief Valves for Hot Water Supply Systems, ANSI Z21.22. The T&P Relief
Valve’s relief pressure must not exceed the working pressure rating of the
water heater as stated on the rating plate.
Maintain the T&P Relief Valve properly. Follow the maintenance instructions
provided by the manufacturer of the T&P Relief Valve (label attached to T&P
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 5
SAFETY
IMPORTANT SAFETY INFORMATION
Relief Valve). An explosion could occur
if the T&P Relief Valve or discharge pipe is blocked. Do not cap or plug the
T&P Relief Valve or discharge pipe.
Fire and Explosion Risk if Hot Water is Not Used for Two Weeks or More.
CAUTION! Hydrogen gas builds up in a hot water system when it is not used for
a long period (two weeks or more). Hydrogen gas is extremely flammable. If the
hot water system has not been used for two weeks or more, open a hot water
faucet for several minutes at the kitchen sink before using any electrical
appliances connected to the hot water system. If hydrogen is present there
will probably be an unusual sound such as “air” escaping through the pipe as
hot water begins to flow. Do not smoke or have an open flame or other ignition
source near the faucet while it is open.
Carbon Monoxide Risk
WARNING! This water heater operates by burning gas. Carbon monoxide is a
colorless, odorless, gas
that is a by-product of burning of fuels such as coal, wood, charcoal, oil,
kerosene, propane, and natural gas. Breathing excessive and abnormal amounts
of carbon monoxide can cause carbon monoxide poisoning, resulting in serious
injury or death. This water heater must be supplied with adequate combustion
air and must be properly vented to the outdoors. Have a qualified person
(licensed plumber, authorized gas company personnel, or authorized service
technician) install the venting
system using these installation instructions. When the installation is
complete, check the vent’s draft using the instructions on pages 23-24.
· Install a fuel gas and carbon monoxide detector in the living areas of your
home.
· Do not install this water heater in a mobile home or manufactured housing.
· Failure to follow these instructions can result in serious injury or death
from carbon monoxide poisoning.
Burn Risk
This water heater’s venting system can become hot enough to burn. Do not touch
the venting system while water heater is on, or until the water heater is
turned off and the venting allowed to cool.
Installation Accessories
Figure 1 -Gas Water Heater Hook-Up Kit
Figure 2 -Install a Pressure Reducing Valve set to 50 to 60 PSI.
6 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
GETTING STARTED
1 Review all of the instructions before you begin work. If you aren’t sure
that you can safely and properly do this work yourself, call your Lowe’s®
store to arrange for Professional Installation (you may also call a qualifi ed
person of your choice, such as a licensed plumber, to have the work done).
Improper installation can damage the water heater, your home and other
property, and can present risks of serious injury or death.
2 This water heater is designcertified by CSA International as a Category I,
non-direct vented water heater which takes its combustion air either from the
installation area or from air ducted to the unit from the outside. This water
heater must be installed according to all local and state codes or, in the
absence of local and state codes, the “National Fuel Gas Code”, ANSI
Z223.1(NFPA 54)-current edition. This is available from the following:
CSA America, Inc. 8501 East Pleasant Valley Road Cleveland, OH 44131
National Fire Protection Association 1 Batterymarch Park Quincy, MA 02269
Check with local code officials about codes governing this installation. Have
your installation inspected by a code official to ensure the installation
meets all local codes.
NOTICE: If you lack the necessary skills required to properly install
this water heater, or you have difficulty following the instructions, you
should not proceed but have a qualified person perform the installation of
this water heater.
Massachusetts code requires this water heater to be installed in accordance
with Massachusetts 248-CMR 2.00 and 248-CMR 5.00: State Plumbing Code. Other
local and state authorities may have similar requirements or other codes
applicable to the installation of this water heater.
Before you start, be sure you
3 have the following tools and
supplies:
· Common plumbing tools (depending on what type of water pipes you have).
· Teflon® tape or pipe joint compound approved for potable water.
· For homes with copper pipes, you may purchase a Gas Water Heater Hook-Up Kit
(available from
· Lowes®) with compression fittings that don’t require soldering. This kit
includes two 12″ flex water lines, two compression fittings, an 18″ flexible
gas line, two nipples, and Teflon® tape.
· For homes with plastic pipe, use threaded connectors suitable for the
specific type of plastic pipe used: CPVC or PEX (cross-linked polyethylene).
Do not use PVC pipe.
· Non-corrosive gas leak detection solution made from hand dishwashing soap
mixed with water (1 part soap to 15 parts water) or children’s soap bubbles
and a small, soft-bristled brush.
· An appliance dolly or hand trck to move the water heater.
Recommended Accessories
· A metal drain pan. · Automatic water leak detection
and shut-off device. · Pressure Reducing Valve. · Thermal Expansion Tank. ·
Thermostatic Mixing Valves at each
point-of-use. · Fuel gas and carbon monoxide
detector.
Combustion and Ventilation Air Supply
Before installing the water heater, you must determine the amount of air
needed to supply this water heater and any other gas appliances in the same
area and provide adequate air for combustion and ventilation. Consult a
qualified person if you’re unsure of the proper way to supply air to your
water
heater.
WARNING! This gas water heater requires an adequate source of clean air for
combustion and ventilation. Without sufficient air, your water heater will
have frequent pilot outages and may emit excessive and abnormal amounts of
carbon monoxide.
Before beginning:
Calculate total BTU/HR rating of all appliances.
To calculate the combustion air and ventilation required, add up the total
BTU/HR ratings of all gas burning appliances (e.g., water heaters, furnaces,
clothes dryers) in the same area.
Your water heater’s BTU/HR rating is on the data plate, located next to the
gas control valve/thermostat. The BTU/HR ratings should be on the other
appliances’ data plates. If you have trouble determining the BTU/HR ratings,
contact the manufacturer or have a qualified person determine the ventilation
requirements. NOTICE: If you are replacing your old water heater with one that
has a higher BTU/HR rating, the amount of ventilation required may be greater.
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 7
Example:
Gas Burning Appliance BTU/HR Rating Gas Water Heater 40,000 Furnace 75,000
Dryer 20,000
Total 135,000
Your Appliances:
Gas Burning Appliance BTU/HR Rating Gas Water Heater
Total
Table 2 provides examples of minimum square footage (area) required for
various BTU/HR totals. Areas used for storage or which contain large objects
containing less air than is assumed for the room sizes in Table 2 see Option
A for more specific calculations.
Table 2 BTU/HR Input 30,000 45,000 60,000 75,000 90,000 105,000 120,000 135,000
Minimum Square Feet with 8′ Ceiling 188 281 375 469 563 657 750 844
Option A: Installation without outside ventilation (not recommended)
Ventilation with outside air is recommended for all installations. Even if the
water heater is installed in a large, open room inside the house, outdoor air
is usually needed because modern homes are very tightly sealed and often do
not supply enough air to the water heater. However, when installed in a large
indoor space, it may be possible to provide enough air without outside
ventilation. If you are unsure if your installation location has enough
ventilation, contact your local gas utility company or code officials for a
safety inspection. The following instructions will help determine if it may be
possible to install without outside ventilation. Even if this may be possible,
you will need to conduct the vent draft test on pages 23-24 when installation
is finished. If there is not enough ventilation, you will need to ventilate
with outside air.
Typical Room with 8′ Ceiling
9 x 21
14 x 20
15 x 25
15 x 31
20 x 28
20 x 33
25 x 30
28 x 30
Check for Chemicals
Installations where corrosive chemicals may be present require outside air.
Air for combustion and ventilation must be clean and free of corrosive or
acid-forming chemicals such as sulfur, fluorine, and chlorine. Ventilation
with outside air will reduce these chemicals, but it may not completely
eliminate them. Failure due to corrosive chemicals is not covered by the
warranty. Examples of locations that require outside air due to chemicals
include:
· Beauty salons
· Photo processing labs
· Indoor pools
· Laundry, hobby, or craft rooms
· Chemical storage areas
Products such as aerosol sprays, detergents, bleaches, cleaning solvents,
gasoline, air fresheners, paint and varnish removers, and refrigerants should
not be stored or used near the water heater.
A1: Calculate the air volume of the room
Air requirements depend on the size of the room.
Floor Area (Square feet) X Ceiling Height (feet) = Room Volume (cubic feet)
If there are large objects in the room (e.g., refrigerator, furnace, car),
subtract their volume from the volume of the room to get a better estimate of
the air available.
Room Volume Object Volume = Air Volume
8 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
GETTING STARTED
A2: Calculate required air volume
A water heater installed in an unconfined attic or garage requires that the
space be at least 50 cubic feet per 1,000 BTU/ HR of the total input for all
gas burning appliances in the same area.
[Total BTU/HR/1000] x 50 = Cubic feet of air required.
Example: (135,000 / 1000) x 50 = 6,750 If the air volume of the room is less
than the required air volume, you must provide two permanent outside air
openings that draw in sufficient air. Use Option B.
If the air volume of the room is greater than the required air volume, it may
be possible to install the water heater without outside ventilation.
A3: Check that combustion ventilation is adequate
Because modern homes are often wellsealed to prevent drafts, even a large room
may not provide enough combustion air without ventilation. To confirm that
your installation has enough combustion air, conduct the vent draft test on
pages 23-24 when installation is finished.
Option B: Install with outside ventilation
Ventilation with outside air is recommended, and, for most installations, is
needed. There may be existing ventilation that is adequate, or you may need to
add more ventilation.
Supplying outside air to typically requires two openings. One opening must be
within 12 inches from the floor and the second opening must be within 12
inches from the ceiling. Although a single opening is not preferred, you may
use a single opening to outside air if the mini- mum free area is sized
according to Table 3. Two openings must be used when ventilating with air from
another room.
The outside air can be taken from a crawl space or attic open to the outdoors
and adequately ventilated. You may use vertical or horizontal ducts.
B2: Determine type of ventilation
There are several types of ventilation that can be used :
1. Direct to outdoors
2. Vertical ducts 3. Horizontal ducts 4. Single opening (not recom-
mended; must be at least 100 square inches. Not appropriate for confined
spaces smaller than 50 cubic feet per 1,000 BTU/HR as calculated in section A
or when getting air from another room.) 5. From a larger room inside the house
(not recommended refer to section A above to determine if the combined
volume of the rooms may be adequate).
B3: Determine minimum free area required for each vent opening
The size of the vent openings depends on the total BTU/HR rating of all
appliances in the space (use your calculation from “Before beginning”) and the
type of vent used. Table 3 provides the minimum free area for each vent
opening depending on the type of ventilation.
B4: Calculate minimum size of vent openings and ducts
The vent cross-sectional area needed to provide the free area depends on the
covering on the vent openings. Typical vents use louvers or grilles to protect
the opening. The louver or grill itself blocks some of the free area, so the
opening may need to be larger to meet the minimum free area requirements.
Use the following formula to calculate the required cross-sectional area:
Cross-sectional area = minimum free area required ÷ percent free area of
covering (in decimals e.g., 60% = .6)
Table 3
Minimum Free Area of Permanent Openings for Ventilation and Combustion Air Supply All Air from Outdoors Only.
Based on the total BTU/HR input rating for all gas burning appliances within a confined space.
Opening Source
Minimum Free Area Per Opening (sq. in.)
*Direct to outdoors 1 sq. in. per 4,000 BTU/HR (see figure on page 10)
Vertical ducts
1 sq. in. per 4,000 BTU/HR (see figure on page 10)
Horizontal ducts
1 sq. in. per 2,000 BTU/HR (see figure on page 10)
Single Opening
1 sq. in. per 3,000 BTU/HR (see figure on page 10)
*These openings connect directly with the outdoors through a ventilated attic, a ventilated crawl space, or through an outside wall.
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 9
For example, an installation area that requires openings with 100 square
inches of free area would need 134 square inch openings if using metal louvers
rated at 75% free area (100 sq. in. ÷ .75 = 134 sq. in.).
If you do not know the % free area for your louver or grill, use the following
values:
· For wood louvers or grilles: 20%
· For metal louvers or grilles: 60%
Follow these rules to ensure that vents and ducts provide adequate air flow:
· Each vent opening must be no smaller than 100 square inches .
· Ducts must have the same crosssectional area as free area of the opening.
· Rectangular ducts must have a minimum dimension of no less than three inches
.
· All screens must have mesh ¼” or larger.
· Moveable louvers must be locked open or interconnected with the equipment so
that they open automatically during operation.
· Keep louvers and grills clean and free of debris or other obstructions.
B5: Check that air source is clean and free of chemicals
Air for combustion and ventilation must be clean and free of corrosive or
flammable chemicals. A failure due to corrosive chemicals in the air is not
covered by the warranty. Combustion air must be free of acid-forming chemicals
such as sulfur, fluorine, and chlorine. Be sure that air at the vent inlets is
free of such chemicals.
B6: Check that combustion ventilation is adequate
To confirm that your installation has enough combustion air, conduct the vent
draft test on pages 23-24 when installation is finished.
Combustion Air Supply Options
Figure 3 -Direct to outdoors openings
Figure 5 -Horizontal duct openings Figure 6 -Single opening
Figure 4 -Vertical duct openings
10 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
Venting
WARNING! Carbon Monoxide Hazard. This water heater must be supplied with
adequate air and vented to outdoors. The vent system must be installed by a
qualified person. Examples of a qualified person include gas technicians,
authorized gas company personnel, and authorized service technicians. Failure
to properly vent the water heater can result in severe injury or death from
carbon monoxide poisoning.
The vent system must be installed according to local and state codes, or in
the absence of local or state codes, the current edition of the National Fuel
Gas Code, ANSI Z223.1 (NFPA 54). Do not common vent this water heater with any
power vented appliance. Do not use a vent damper anywhere in the vent system
of this water heater.
To reduce the risk of carbon monoxide poisoning, install a fuel gas and carbon
monoxide detector. Install and maintain the detector in accordance with the
manufacturer’s instructions and local codes.
Replacing a Water Heater Using the Existing Vent System
Read the “Installing a New Vent System” section of this manual and make sure
your vent system is properly installed. Inspect the existing vent system for
obstructions, corrosion, and proper installation. Repair or replace if
necessary. The existing vent system must be UL listed Type B double wall or
single wall metal vent pipe of either 3 inch or 4 inch diameter and installed
according to the vent manufacturer’s instructions and the terms of its
listing. Do not use other materials such as dryer vent hose.
Installing a New Vent System
The vent pipe must meet the following specifications:
Type of Material UL listed Type B double wall or single wall metal vent pipe
must be used. Local codes may be more restrictive and may not allow single
wall vent pipe. Single-wall vent pipe cannot be used for water heaters located
in attics and may not pass through attic spaces, crawl spaces, or any confined
or inaccessible location. Single-wall vent pipe cannot pass through any
interior wall.
Clearance to Combustible Materials The vent pipe cannot pass through any
ceiling, floor, firewall, or fire partition. Any part of the vent system must
maintain the following clearances from any combustible materials:
· Single-wall vent pipe must maintain a six inch clearance from combustible
materials.
· The clearance from combustible materials of UL listed Type B double-wall
vent pipe is specified by the manufacturer of the vent pipe. UL listed Type B
double-wall vent pipe may pass through walls or partitions constructed of
combustible material if the minimum clearance specified by the manufacturer of
the vent pipe is maintained.
Vent Installation To improve the flow of exhaust gases, we recommend that a
minimum of 12 inches of vertical vent pipe be installed on the draft hood
prior to any elbow. A portion of the vent pipe (up to 75% of the total
vertical height) can be horizontal, but the termination must be vertical. For
the horizontal section, install without dips or sags with an
upward slope of at least ¼ inch per foot. Install pipe avoiding unnecessary
bends. Pipe joints must be fastened by sheet metal screws or other approved
means. Support the pipe to maintain clearances and to avoid separation of
joints or other damage. Vent pipe must be accessible for cleaning, inspection,
and replacement.
Terminations If local codes allow, this water heater may be terminated into an
existing chimney using the instructions below. Otherwise, this water heater’s
vent must terminate vertically (sidewall or other horizontal terminations are
not allowed).
Chimney Termination
Figure 7 -Chimney termination vent system
NOTICE: Before connecting a vent to a chimney, make sure the chimney
passageway is clear and free of obstructions. The chimney must be cleaned if
previously used for venting solid fuel appliances or fireplaces. Also consult
local and state codes for proper chimney sizing and application or, in the
absence of local and state codes, the “National Fuel Gas Code”, ANSI
Z223.1(NFPA 54)-current edition.
· The vent pipe must be installed above the extreme bottom of the chimney to
prevent potentially blocking the flue gases.
· The vent pipe must be firmly attached and sealed to prevent it from falling
out.
· To aid in removing the vent pipe, a thimble or slip joint may be used.
· The vent pipe must not extend beyond the inner edge of the chimney as it may
restrict the space between it and the opposite wall of the chimney.
Do not terminate the vent pipe in a chimney that has not been certified for
this purpose. Some local codes may prohibit the termination of vent connectors
in a masonry chimney.
Common (combined) venting is allowable with vertical Type B vent systems and
lined masonry chimneys as long as proper draft for the water heater is
established under all conditions of operation. Do not common vent this water
heater with any power vented appliance.
Vertical Termination NOTICE: The gas vent must be terminated in a vertical
position to facilitate the removal of exhaust gases.
Vertical exhaust vents must terminate with a listed cap or other roof assembly
and be installed according to their manufacturer’s instructions. An unused
chimney flue or masonry enclosure may be used as a passageway for the
installation of vent pipe. Do not common vent this water heater with any power
vented appliance. The following figures are examples of vent pipe system
installations and may or may not be suitable for your specific application.
Consult the “National Fuel Gas Code”, NFPA 54, ANSI Z223.1-current edition and
local codes.
Figure 8 -Vertical gas vent system with type B double wall vent pipe
Figure 9 -Venting through a chimney with type B double wall vent pipe
Gas Piping
Gas piping must be installed according to local and state codes or, in the
absence of local and state codes, the “National Fuel Gas Code”, ANSI
Z223.1(NFPA 54)-current edition. NOTICE: When installing gas piping, apply
pipe joint compound or Teflon® tape approved for fuel gases.
Figure 10 -Gas Piping
1. Install a readily accessible manual shut-off valve in the gas supply line
as recommended by the local utility. Know the location of this valve and how
to turn off the gas to this unit.
2. Install a Sediment Trap as shown in the Gas Piping figure below. The
Sediment Trap must be no less than three inches long for the accumulation of
dirt, foreign material, and water droplets.
3. Install a ground joint union between the gas control valve and the manual
gas shut-off valve. This is to allow easy removal of the gas control valve.
4. Turn the gas supply on and check for leaks. Use a small, soft-bristled
brush to apply a hand dishwashing soap and water mixture (1 part soap to 15
parts water) or children’s soap bubbles to all connection points of the gas
piping. Saturate all the connections and check for gas leaks (which will
appear as small bubbles). If any leaks are detected, tighten the appropriate
connection(s) and re-check.
Gas Pressure
NOTICE: When testing gas pipes with a test pressure of more than ½ psi (3.5
kPa), disconnect the gas line at the manual shut off valve and cap the gas
line. Do not subject the water heater’s gas control valve or manual shut off
valve to more than ½ psi (3.5 kPa) pressure for any reason. If you are
pressure testing the gas line with test pressure of ½ psi (3.5 kPa) or less,
you may isolate the water heater from the gas line by closing the manual shut
off valve.
12 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
TYPICAL MIXING VALVE INSTALLATION COMBINATION SPACE HEATING / POTABLE WATER HEATING SYSTEM TEMPERED WATER TO FIXTURES (MUST MEET TEMPS LISTED IN MASS. CODE 248 CMR )
CHECK VALVE
EXPANSION TANK
COLD WATER INLET
VACUUM RELIEF VALVE
CHECK VALVE (1/8″ HOLE
SHUT-OFF VALVE
DRILLED IN CLAPPER)
MUST BE VERTICAL TO REMOVE AIR BUBBLES
MIXING VALVE (MUST BE INSTALLED BELOW TOP OF WATER HEATER AS PER
MANUFACTURER’S RECOMMENDATIONS)
WATER HEATER ACCEPTED BY THE BOARD FOR INSTALLATION IN MASSACHUSETTS.
UNION
HOT WATER
OUT
UNION
FLOW CONTROL VALVE
PUMP *
TEMP/ PRESSURE RELIEF VALVE
OUT
IN
TO AIR HANDLER
COIL
SEE NOTE
SHUT-OFF
VALVE *
AIR HANDLER
100′-0″ MAXIMUM DISTANCE
FROM WATER HEATER TO FAN COIL AND BACK
(DEVELOPED LENGTH) NOT
INCLUDING COIL IN HEATING UNIT.
- MASSACHUSETTS INSTALLATION REQUIREMENTS:
1.) CONNECT ELECTRONICALLY-CONTROLLED TIMER TO AN ALL-BRONZE PUMP. PUMP MUST ACTIVATE EVERY 6 HOURS FOR 60 SECONDS. TURN PUMP TIMER OFF BEFORE CLOSING PIPING LOOP SHUT-OFF VALVE.
2.) ALL WATER PIPING MUST BE INSTALLED AND INSULATED IN ACCORDANCE WITH MASSACHUSETTS CODE (248 CMR & 780 CMR).
3.) PIPING LOOP BETWEEN WATER HEATER AND AIR HANDLER MUST BE INSTALLED IN COMPLIANCE WITH 248 CMR.
REQUIRED FOR MASSACHUSETTS.
PIPING FROM THE TOP OF THE WATER HEATER WITH TEES IS ACCEPTABLE.
Figure 11 -Combustion Space Heating and Potable Water (Typical Installation)
Some water heater models are equipped
with inlet/outlet connections for use with space heating applications. If this
water heater is to be used to supply both space
heating and domestic potable (drinking) water, the instructions listed below
must be followed.
· Do not use with piping that has been treated with chromates, boiler seal or
other chemicals and do not add any chemicals to the water heater piping.
· If the space heating system requires water temperatures in excess of 120°F,
install a Thermostatic Mixing Valve
· This water heater is suitable for
in the domestic (potable) hot water
combination water (potable) heating and space heating and not suitable for
supply at each point-of-use to limit the risk of scald injury. Install the mixing
space heating applications only. · Be sure to follow the manual(s)
valve per its manufacturer’s instructions.
shipped with the air handler system. · Pumps, valves, piping, and fittings
· This water heater is not to be used as a replacement for an existing boiler
must be compatible with potable water.
installation.
· A properly installed flow control valve
is required to prevent thermosiphon-
ing. Thermosiphoning is the result of a
continuous flow of water through the air handler circuit during the off cycle.
· The domestic hot water line from the water heater should be vertical past
any mixing valve or supply line to the air handler to remove air bubbles from
the system. Otherwise, these bubbles will be trapped in the air handler heat
exchanger coil, reducing efficiency.
· Do not connect the water heater to any system or components previously used
with non-potable water heating appliances when used to supply potable water.
Solar Installation
If this water heater is used as a solar storage heater or as a backup for the
solar system, the water supply temperatures to the water heater tank may be in
excess of 120°F. A Thermostatic Mixing Valve or other temperature limiting
valve must be installed in the water supply line to limit the supply
temperature to 120°F. The unit must be set to Standard Mode. (See Operating
Modes in Operation section, pages 24 and 25.)
NOTICE: Solar water heating systems can often supply water with temperatures
exceeding 180°F and may result in water heater malfunction.
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 13
INSTALLATION
Step 1:
Verify that your home is equipped and up-to-date for proper operation
Installing a new water heater is the perfect time to examine your home’s
plumbing system and make sure the system is up to current code standards.
There have likely been plumbing code changes since the old water heater was
installed. We recommend installing the following accessories and any other
needed changes to bring your home up to the latest code requirements. Updating
your plumbing system can help extend the life of your water heater, avoid
damage to your home and property, and reduce the risk of serious injuries or
death. Inspect your home and install any devices you need to comply with
current codes and assure that your new water heater performs at its best.
Check with your local plumbing official for more information.
Water pressure Most codes allow a maximum incoming water pressure of 80 psi
(we recommend a working pressure no higher than 50-60 psi). Check your home’s
water pressure with a pressure gauge and adjust if necessary. High water
pressure can damage the water heater, piping, and other appliances.
HOW: Purchase an inexpensive water pressure gauge from Lowe’s®. Connect the
water pressure gauge to
an outside faucet and measure the maximum water pressure experienced
throughout a 24-hour period (highest water pressures often occur at night).
Figure 12 -Use a Water Pressure Gauge to make sure your home’s water pressure
is not too high.
To adjust your home’s water pressure: Locate your home’s Pressure Reducing
Valve (PRV) on the main incoming (cold) water supply line and adjust the water
pressure control to between 50 and 60 psi. If your home does not have a
Pressure Reducing Valve, install a PRV on the home’s main water supply line
and set it to between 50 and 60 psi. Pressure Reducing Valves are available at
Lowe’s®. BACKGROUND: Over the years, many utilities have increased water
supply pressures so they can serve more homes. In some homes today, pressures
can exceed 100 psi. High water pressures can damage water heaters, causing
premature leaks. If you have replaced toilet valves, had a water heater leak,
or had to repair appliances connected to the plumbing system, pay particular
attention to your home’s water pressure. When purchasing a PRV, make sure the
PRV has a built-in bypass.
Water pressure increase caused by thermal expansion
Verify that you have a properly sized Thermal Expansion Tank. We recommend
installing an expansion tank if your home does not have one. Plumbing codes
require a properly pressurized, properly sized Thermal Expansion Tank in
almost all homes.
Figure 13 -A Thermal Expansion Tank helps protect the home’s plumbing system
from pressure spikes.
HOW: Connect the Thermal Expansion Tank (available at at Lowe’s®) to the cold
water supply line near the water heater. The expansion tank contains a bladder
and an air charge. To work properly, the Thermal Expansion Tank must be sized
according to the water heater’s tank capacity and pressurized to match the
home’s incoming water pressure. Refer to the instructions provided with the
Thermal Expansion Tank for installation details.
BACKGROUND: Water expands when heated, and the increased volume of water must
have a place to go, or thermal expansion will cause large increases in water
pressure (despite
the use of a Pressure Reducing Valve in the home’s main water supply line).
The Safe Drinking Water Act of 1974 requires the use of backflow preventers
and check valves to restrict water from your home reentering the public water
system. Backflow preventers are often installed in water meters and may not be
readily visible. As a result, most all plumbing systems today are now
“closed,” and almost all homes now need a Thermal Expansion Tank.
A Thermal Expansion Tank is a practical and inexpensive way to help avoid
damage to the water heater, washing machine, dishwasher, ice maker, and even
toilet valves. If your toilet occasionally runs for no apparent reason
(usually briefly at night), that may be due to thermal expansion increasing
the water pressure temporarily.
Water Pipe and Tank Leaks
DISCHARGE PIPE (DO NOT CAP OR PLUG)
METAL DRAIN PAN 6″ MAXIMUM AIR GAP
AT LEAST 2″ GREATER THAN THE DIAMETER OF THE WATER HEATER. PIPED TO AN
ADEQUATE DRAIN
Figure 14 -A metal drain pan piped to an adequate drain can help protect
flooring from leaks and drips.
Leaks from plumbing pipes or from the water heater itself can damage property and could cause a fire risk. · Install an automatic leak detec-
tion and shutoff device (available at Lowe’s®). These devices can detect water
leaks and can shut off the water heater’s water supply if a leak occurs. ·
Install a metal drain pan (available at Lowe’s®) under the water heater to
catch condensation or leaks from the piping connections or tank. Most codes
require, and we recommend, installing the water heater in a metal drain pan
that is piped to an adequate drain. The drain pan must be at least two inches
wider than the diameter of the water heater. Install the drain pan so the
water level would be limited to a maximum depth of 1-3/4″. The pan must not
restrict air flow to the burner.
Water Temperature Regulation
Install Thermostatic Mixing Valves to regulate the temperature of the water
supplied to each point-of-use (for example, kitchen sink, bathroom sink, bath,
shower). Install and adjust the mixing valve according to its manufacturer’s
instructions.
WARNING! Even if the water heater’s thermostat is set to a relatively low
temperature, hot water can scald. Install Thermostatic Mixing Valves at each
point-of-use to reduce the risk of scalding.
Figure 15 -Thermostatic Mixing Valves installed at each point-of-use can help
avoid scalding
BACKGROUND: A Thermostatic Mixing Valve, installed at each point-of-use, mixes
hot water from the water heater with cold water to more precisely regulate the
temperature of hot water supplied to fixtures. If you aren’t sure if your
plumbing system is equipped with properly installed and adjusted Thermostatic
Mixing Valves at each point where hot water is used, contact a qualified
person.
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 15
Step 2: Verify that the location is appropriate
WARNING! Do not store or use flammable materials, vapors, or liquids in the
same location where this water heater is installed.
Before installing your water heater, ensure that it will be located: · Indoors
in an area with adequate
air supply. · In an area that will not freeze. · As close as possible to a
chimney
or vent. · In a metal drain pan piped to an
adequate drain. · In an area suitable for vertical
installation. · In an area with adequate space
(clearances) for periodic servicing (there must be a minimum of 24 inches of
front clearance). · In an area that allows a minimum clearance from
combustible surfaces as stated on the data plate. · On a floor that can
support the weight of a water heater full of water. · Within 19 feet of a
120VAC outlet. Do not use an extension cord. You will also want to follow
these guidelines while considering an appropriate location: · Do not install
near air-moving devices such as exhaust fans, ventilation systems, or clothes
dryers. · Do not obtain ventilating air for the furnace/air handler from the
same space as the water heater. Ensure that any return air ducts near the
water heater are sealed.
· If the water heater is located in an area subject to lint, dust, or oily
vapors, at least annually check and clean the air filter. See Maintenance
section for steps on cleaning the air filter.
· Do not install in a bathroom, bedroom, or any occupied room normally kept
closed.
· If the water heater is installed directly on carpeting, it shall be
installed on a metal or wood panel extending beyond the full width and depth
of the water heater by at least 3 in (76.2mm) in any direction. If the water
heater is installed in an alcove or closet, the entire floor shall be covered
by the aforestated panel.
· If your area is prone to earthquakes, use special straps as required by
local building codes.
NOTICE: The state of California requires bracing, anchoring, or strapping the
water heater to avoid its moving during an earthquake. Contact local utilities
for code requirements in your area, visit http://www.dsa.dgs. ca.gov, or call
1-916-445-8100 and request
instructions. Other locations may have similar requirements. Check with your
local and state authorities.
· Do not install in a location prone to physical damage by vehicles, flooding,
or other risks.
Vehicle Stop
Drain Pan
Drain
Figure 16 -In a garage, install a vehicle stop to avoid water heater damage.
· Avoid locations such as attics, upper floors, or where a leak might damage
the structure or furnishings. Due to the normal corrosive action of water, the
tank will eventually leak. To minimize property damage from leaks, inspect and
maintain your water heater in accordance with this manual’s instructions.
Install a metal drain pan under the water heater piped to an adequate drain.
Inspect the drain pan, pipes, and surrounding area regularly and fix any leaks
found.
Step 3:
Removing the old water heater
1 Read each installation step and decide if you have the necessary skills to
install the water heater. Only proceed if you are comfortable you can safely
perform the work. If you are not sure, have a qualified person perform the
installation.
On the old water heater, turn
2 the control knob on the gas
control valve to the OFF position. See Figure 17.
16 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
drain, outside, or in buckets. (Sedi-
ment in the bottom of the tank may clog the valve and prevent it from
draining. If you can’t get the tank to drain, contact a qualified person.)
Turn the cold water supply
6 valve OFF.
Gas control knob
Figure 17 -Turn gas control/temperature knob OFF.
3 Turn the manual gas valve for the water heater’s supply line OFF. Open a hot
water faucet and
4 let the hot water run until it is
cool (This may take 10 min utes or longer).
Figure 19 -Cold water supply in off position.
Using a standard flat-blade
7 screwdriver, open the drain
valve. Sediment build up in the bottom of the water heater may hinder or
prevent draining.
Figure 21 -Removing the T&P Relief Valve discharge pipe.
10 Allow the vent pipe and draft hood to cool. Once cooled, disconnect the
vent pipe from the draft hood. You may need to support the vent pipe until the
new water heater is in place.
Figure 18 -Let the hot water run until it is cool.
WARNING! Be sure the water runs cool before draining the tank to reduce the
risk of scalding.
5 Connect a garden hose to the drain valve and place the other end of the hose
in a
Figure 20 -Draining the old water heater.
Also open a hot water faucet
8 to help the water in the tank
drain faster. When the tank is empty,
9 disconnect the Temperature &
Pressure (T&P) Relief Valve discharge pipe. You may be able to reuse the
discharge pipe, but do not reuse the old T&P Relief Valve. A new T&P Relief
Valve comes with your new water heater.
Figure 22 -Disconnect the vent pipe from the draft hood.
Disconnect the water pipes.
11 Many water pipes are con-
nected by a threaded union which can be disconnected with wrenches. If you
must cut the water pipes, cut the pipes close to the water heater’s inlet and
outlet connections, leaving the water pipes as long as possible. If necessary,
you can make them shorter later when you install the new water heater.
12 Confirm the manual gas valve for the water heater’s supply
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 17
line is turned off. Disconnect the gas line from the water heater’s gas
control valve and cap it.
Remove the old water heater.
13 Use an appliance dolly or
hand truck to move the water heater. WARNING! Use two or more people to remove
or install a water heater. Failure to do so can result in back or other
injury.
Step 4: Installing the New Water Heater
Completely read all instruc-
1 tions before beginning. If you
are not sure you can safely complete the installation, seek assistance from
any of the following sources: · Lowe’s® Professional Installation
is available for this product and the work is guaranteed. Call your Lowe’s®
store to have this water heater installed. · Schedule an appointment with a
qualified person to install your water heater. · Call our Technical Assistance
Hotline at 1-877-817-6750.
2 Install a metal drain pan that is piped to an adequate drain.
METAL DRAIN PAN
AT LEAST 2″ GREATER THAN THE DIAMETER OF THE WATER HEATER. PIPED TO AN
ADEQUATE DRAIN
Figure 23 -Metal drain pan piped to drain.
3 Set the water heater in place taking care not to damage the drain pan. When
installing directly on carpet, the water heater must be installed on a wood or
metal base that extends beyond the dimensions of the water heater (width and
depth) by at least 3 inches (76.2 mm) in any direction. If the water heater is
installed on carpet in an alcove or closet, the entire floor must be covered
by a wood or metal panel. NOTICE: Most codes require setting the water heater
in a metal drain pan piped to an adequate drain. The drain pan helps avoid
property damage which may occur from condensation or leaks in the piping
connections or tank. The drain pan must be at least two inches wider than the
diameter of the water heater. Install the drain pan so the water level is
limited to a maximum depth of 1-3/4″.
4 Verify that the water heater is set in place properly. Check that: · There
is adequate space to install
the T&P Relief Valve discharge pipe and that it can be piped to a separate
drain (and not into the drain pan). · There is adequate access and space
around the water heater for future maintenance. · The water heater is
installed vertically.
Step 5:
Check the Air Filter
This water heater is equipped with a base-ring air filter. Before proceeding
to the next step, visually check the filter to ensure it is properly seated in
the base-ring. Do not operate the water heater without a clean air filter in
place.
step 6:
Connect the Temperature and Pressure (T&P) Relief Valve/Pipe
Most T&P Relief Valves are preinstalled at the factory. In some cases, they
are shipped in the carton and must be installed in the opening marked “T&P
Relief Valve” and according to local codes.
Figure 24 -Temperature and Pressure Relief Valve
WARNING! To avoid serious injury or death from explosion, install a T&P Relief
Valve according to the following instructions:
18 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
1 If the T&P Relief Valve was not factory installed, install the new T&P
Relief Valve that came with your water heater. Do not reuse an old T&P Relief
Valve. · The discharge pipe should be at
least 3/4″ inside diameter and sloped for proper drainage. Install it to allow
complete drainage of both the T&P Relief Valve and the discharge pipe.
DISCHARGE PIPE (DO NOT CAP OR PLUG) 6″ MAXIMUM AIR GAP ADEQUATE DRAIN
Figure 25 -Temperature and Pressure Relief Valve Pipe (Discharge Pipe)
· The discharge pipe must not be smaller than the pipe size of the T&P Relief
Valve. The pipe must also be able to withstand 250°F (121°C) without
distortion. Use only copper or CPVC pipe. Do not use any other type of pipe,
such as PVC, iron, flexible plastic pipe, or any type of hose.
· Terminate the discharge pipe a maximum of six inches above a floor drain or
outside the building. Do not drain the discharge pipe into the drain pan;
instead pipe it separately to an adequate drain. In cold climates, terminate
the discharge pipe inside the building to an adequate drain. Outside drains
could freeze and obstruct the drain line–protect the discharge pipe from
freezing.
· Do not place any valve or other
restriction between the tank and T&P Relief Valve. Do not cap, block, plug, or insert any valve between the T&P Relief Valve and the end of the discharge pipe. Do not insert or install any reducer in the discharge pipe.
Step 7:
Install Shutoff and Thermostatic Mixing Valves
1 If one is not already installed, install a manual shutoff valve in the cold
water line that supplies the water heater. Install the shutoff valve near the
water heater so that it is readily accessible. Only use a full-flow ball or
gate valve compatible with potable water.
2 Install a Thermostatic Mixing Valve at each point-of-use (for example,
kitchen sink, bathroom sink, bath, shower) per the valve manufacturer’s
instructions.
Figure 26 -Install Thermostatic Mixing Valves at each point where hot water
will be used.
WARNING! Even if the water heater’s thermostat is set to a relatively low
temperature, hot water can scald. Install Thermostatic Mixing Valves at each
point-of-use to reduce the risk of scalding.
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 19
3 For water heaters that are fed by a solar water heating system (or any other
preheating system), always install a Thermostatic Mixing Valve or other
temperature limiting device in the inlet water supply line to limit water
supply inlet temperature to 120°F. Solar water heating systems can supply
water with temperatures exceeding 180°F and may result in water heater
malfunction.
WARNING! Hot water provided by solar heating systems can cause severe burns
instantly, resulting in severe injury or death.
IF YOU HAVE COPPER PIPES:
If your home has copper water pipes, you can solder the water pipe connections
or use compression fittings which don’t require soldering. Compression
fittings are easier to install than soldering pipe. Check with local plumbing
officials to determine what types of pipe materials are suitable for your
location. Do not use lead-based solder.
connections contain non-metallic parts which could be damaged. The proper way to connect the water heater to copper water pipes is as follows:
Compression fittings don’t require soldering.
NOTICE: Do not solder pipes while they are attached to the water heater. The
water heater’s inlet and outlet
· Solder a short length of pipe (about a foot or so) to a threaded adapter
using only 95/5 tin-antimony or equivalent solder. Attach the threaded
adapters to the water heater’s
connections (using Teflon® tape or pipe joint compound). Connect the home’s
water pipes by soldering, keeping the connections at the water heater cool
with wet rags.
Step 8:
Connect the Water Supply
Note that all piping and components connected to the water heater must be
suitable for use with potable water.
1 Determine the type of water pipes in your home. Most homes use copper water
pipes, but some use CPVC or crosslinked polyethylene (PEX). Use fittings
appropriate for the type of pipe in your home. Do not use iron or PVC pipe.
2 Connect the cold water supply using 3/4 inch National Pipe Thread “NPT” to
the fitting marked “C” (COLD).
For ease of removing the water heater for service or replacement, connect the
water pipes with a coupling called a union. We recommend using a dielectric-
type union (available at Lowe’s®). Dielectric unions can help prevent
corrosion caused by tiny electric currents common in copper water pipes and
can help extend the life of the water heater
20 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
NOTICE: Most water heater models contain energy saving heat traps in the inlet
and outlet connections. Do not remove the heat traps.
3 Connect the hot water supply using 3/4 inch NPT to the fitting marked “H”
(HOT).
4 Install insulation (or heat tape) on the water pipes especially if the
indoor installation area is subject to freezing temperatures. Insulating the
hot water pipes can increase energy efficiency.
5 Adjust (or install) the home’s Pressure Reducing Valve to 50-60 psi and
install a Thermal Expansion Tank.
Figure 27 -A Pressure Reducing Valve is required if your home’s water pressure
is above 80 psi.
Figure 28 -The Thermal Expansion Tank should be pressurized with air, using a
hand pump, to match the home’s incoming water pressure.
Step 9: Verify Connections and Completely Fill Tank
To remove air from the tank and allow the tank to fill completely with water,
follow these steps:
1 Remove the aerator at the nearest hot water faucet. This allows debris in
plumbing system to be washed out of the pipes.
Turn the cold water supply
2 back on and fill the tank.
3 Open a hot water faucet and allow the water to run until it flows with a
full stream.
4 Let the water run full stream for three minutes.
5 Close the hot water faucet and replace the aerator.
6 Check inlet and outlet connections and water pipes for leaks. Dry pipes
connections so that any drips or leaks will be apparent. Repair any leaks.
Almost all leaks occur at connections and are not a tank leak.
Step 10:
Install Draft Hood 1 Install the new draft hood by
aligning the legs and inserting them into the slots on the flue damper’s
flange. (See Figure 29.) Do not reuse the draft hood from the old water
heater, but rather use the new one that came with your new water heater.
2 Secure the draft hood by bending the leg tips, but do not alter the draft
hood in any way.
Draft Hood
Flue Damper
Draft Hood Leg Tip Twist or bend the leg tips to secure the draft
hood to the flue damper. * Damper orientation may vary.
Figure 29 -Install the new draft hood.
3 Attach the home’s existing vent pipe to the draft hood outlet using an
approved vent adapter (not supplied). Read the Venting section on page 11.
Make sure your home’s venting system complies with the instructions in this
manual and is in good condition.
rd Gas Ultra Low Nox Water Heater Use and Care Guide · 21
Make Gas Connections
The Gas Water Heater Hook-Up Kit (available at Lowe’s®) includes a flexible
gas connector with compression fittings to connect the home’s gas line to the
water heater’s gas control valve. Follow the kit’s installation instructions
to attach the flexible gas connector.
Figure 30 -Flexible gas line connector.
Once you’ve made the gas connections, use a small, soft-bristled brush to
apply a hand dishwashing soap and water mixture or children’s soap bubbles (1
part soap to 15 parts water) to all connection points of the gas line and
flexible gas connector (if used). Make sure to generously coat all the
connections and check for gas leaks (which will appear as small bubbles). If
any leaks are detected, turn the gas supply off, tighten the leaking
connection and re-check.
BEFORE LIGHTING THE WATER HEATER…
Make sure all checklist items have been completed. Water Heater Location
Installation area free of corrosive
or flammable materials, liquids or vapors.
Proper clearances from combustible
surfaces maintained and sufficient room to service the water heater.
Not installed directly on a carpeted
floor.
Metal drain pan installed and piped
to an adequate drain.
Water heater not located near an
air moving device (fan, clothes dryer).
Not in a location with large
amounts of lint, dust, etc. (If so, the air filter or flame arrestor located
on the bottom of the water heater will need to be cleaned more often.)
Combustion Air Supply and Ventilation
Adequate air supply for water
heater and any other nearby gas appliances. If the water heater is installed
in a closet or other small, enclosed space or within the living space of the
house, air supply openings needed.
Are the openings of sufficient size? Ductwork is the same cross-sec-
tional area as the openings?
Outside air openings are preferred
and may be required in tightly built homes. Vent Pipe System
New draft hood, properly installed. Vent pipe securely fastened to
draft hood with screws and supported properly.
Vent pipe made of approved mate-
rial and either 3″ or 4″ in diameter.
Vent system installed according
to local and state codes or, in the
absence of local and state codes, the “National Fuel Gas Code”, ANSI
Z223.1(NFPA 54)-current edition.
Check existing vent system for rust,
restrictions/obstructions.
Water System Piping
Temperature and pressure relief
valve properly installed with a discharge line run to an adequate drain and
protected from freezing.
Water pipes free of leaks. Water heater completely filled with
water.
Thermal Expansion Tank installed Water Pressure Reducing Valve
installed and adjusted to 50-60 psi.
Thermostatic Mixing Valves in-
stalled at each point-of-use.
Gas Supply and Piping
Gas type is the same as that listed
on the water heater’s data plate.
Gas line equipped with shut-off
valve.
Adequate gas pipe size and ap-
proved gas pipe material.
All gas connections and fittings leak
checked and any leaks corrected.
22 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
OPERATION
Lighting Instructions
WARNING! Explosion Hazard Replace viewport if glass is missing or damaged.
Failure to do so can result in death, explosion or fire. Read and understand
these directions thoroughly before attempting to put the water heater into
operation. Make sure the viewport is not missing or damaged. Make sure the
tank is completely filled with water before lighting the pilot. Check the data
plate near the gas control valve to ensure the correct gas type. Do not use
this water heater with any gas other than the one listed on the data plate. If
you have any questions or doubts, consult your gas supplier or gas utility
company. NOTICE! A newly installed water heater will have air in the gas line.
It may take several lighting attempts to clear all the air from the gas line
and light the pilot. Follow these steps to light the pilot:
1 Make sure the manual gas valve for the water heater’s supply line is ON.
Figure 31 -Gas valve in “on” position
2 Plug the water heater into a grounded 120 VAC outlet.
Figure 32 -Move switch to ON position.
3 Move the ON/OFF switch on the gas control valve to the ON position (Figure
32).
4 Turn the gas control valve to the LOW temperature setting (Figure 33). The
water heater will light automatically. Do not try to light the pilot by hand.
Figure 33 -Set knob to LOW setting.
5 When the pilot is lit, the status light will blink a heartbeat (bright, dim,
bright, dim, etc.).
Adjust the gas control knob to the HOT setting.
If you receive a flash code (six flashes followed by a single flash): A.) Turn
the power switch on the gas valve to the OFF position. B.) Unplug the water
heater from the wall outlet. C.) Wait 10 minutes. D.) Repeat steps 1 through
4.
6 Follow these steps if the Status Light does not start flashing a “heartbeat”
after three lighting attempts: A.) Turn off gas to the water heater at the
manual shut-off valve. B.) Move the gas valve’s ON/OFF switch to the OFF
position. C.) Refer to “Troubleshooting-No Hot Water” on page 25. · When a gas
water heater is first lit and the tank is cold, condensation often forms
inside the water heater. You may hear drips or a sizzling sound when the water
heater is first lit, or you may see a small puddle on the floor. Condensation
is not a leak and
will go away once the tank reaches normal operating temperature.
· The air filter at the bottom of the water heater must be cleaned from time
to time. See the Maintenance section for steps on cleaning the air filter. If
the air filter is not cleaned as needed, an LDO fault code may occur. (LDO
faults are diagnosed on page 30.)
Shut down Instructions
Move the ON/OFF switch on the gas control valve to the OFF position. The
status light will stop blinking and stay on for a short time after the water
heater is turned off.
Emergency Shut down
Should overheating occur or the gas supply fail to shut off, follow these
steps:
A.) Turn off gas to the water heater at the manual shut-off valve. B.) Move
the gas valve’s ON/OFF switch to the OFF position. C.) Turn off all electric
power to the water heater. (Unplug it from the 120 VAC outlet.)
Checking the Vent System and Air Supply
Once the water heater is lit and the gas control knob is set to the desired
temperature, the burner will light (if the tank is cold). Perform an air
supply and vent test to make sure the unit is venting properly and the air
supply is adequate:
1 The main burner must be on for this test. With a newly installed water
heater full of cold water, turning the temperature control knob to HOT should
cause the main burner to come on. You can view the burner through the sight
glass at the base of the water heater.
2 Close all windows and doors and turn on all gas appliances and air-moving
devices (range hoods, bathroom exhaust fans, ceiling fans, etc.) in your home.
Also, close any fireplace dampers.
3 Allow the water heater’s main burner to operate for five minutes. Pass a
newly extinguished match approximately one inch from the draft hood’s relief
opening. Smoke from the match should be steadily drawn into the opening
indicating the water heater is getting adequate air and the vent system is
working.
Figure 34 -Test the air supply and vent to make sure the water heater has
adequate air and is venting properly.
4 If the main burner has been operating for five minutes but the match smoke
drifts around or is blown away from the opening, a.) turn off gas to the water
heater at the manual shut-off valve, b.) turn the gas valve switch to the OFF
position, then c.) unplug the water heater from the power outlet. Inspect the
vent system and repair if necessary. In many cases, failure to pass the air
supply and vent test indicates the water heater is not getting enough air or
there is a problem with the vent system. It may be necessary to increase the
air supply by getting air from outside (see page 7). WARNING! Burn Hazard. Do
not touch the vent, doing so can cause burns. If the draft hood does not draw
in smoke from a match after five minutes of main burner operation, shut the
gas supply off, and do not operate the water heater until the vent system and
air supply have been checked by a qualified person and
repaired if necessary. Continuing to operate the water heater in this
condition could lead to serious injury or death from carbon monoxide
poisoning.
Temperature Control System
Adjusting the Temperature
With the installation steps completed, you may adjust the water heater’s
temperature setting if desired.
1 Set the gas valve to the desired temperature. The “HOT” setting sets the
water temperature to approximately 120°F, reducing the risk of scald injury.
You may wish to set a higher temperature to provide hot water for automatic
dishwashers or laundry machines, to provide more hot water capacity, and to
reduce bacterial growth. Higher tank temperatures (140° F) kill bacteria that
cause a condition known as “smelly water” and can reduce the levels of
bacteria that cause water-borne diseases.
Water usage patterns, as well as heat from sources such as solar collectors,
ambient air, and the pilot light can result in temperatures higher than the
thermostat set-point.
WARNING! Higher temperatures increase the risk of scalding, but even at 120°F,
hot water can scald (see Table 1). Install Thermostatic Mixing Valve(s) at
each point-of-use to reduce the risk of scalding.
2 To adjust the water heater’s thermostat:
Figure 35 -Adjust the gas control knob to “HOT”.
Turn the gas control knob on the gas
control valve to the desired setting.
· VAC
55°F
· LOW · HOT · A
91°F 120°F 130°F
· B
140°F
· C
150°F
· VERY HOT 155°F
NOTICE: The temperatures above are
approximates. The actual temperature
of the heated water may vary.
3 Wait for the water to heat up. If you have no hot water after two hours, refer to the Troubleshooting Section ( page 25 ).
NOTICE: If the tank is full of cold water, condensation may form inside the
water heater. This condensation may drop on the burner causing a sizzling
sound. In some cases, you may see a
small puddle on the floor. Condensation is normal and should go away once the
tank reaches its normal operating procedure.
WARNING! If you have increased the temperature setting and the Thermostatic Mixing Valves are not set properly (or not installed) you could scald yourself while checking the temperature.
TROUBLESHOOTING
4 Check water temperature at several points of use in your home (for example,
bathtub faucet, shower, or lavatory sink) and adjust the Thermostatic Mixing
Valves as needed. If you aren’t sure how to adjust the Thermostatic Mixing
Valve settings, or aren’t sure if you have Thermostatic Mixing Valves, contact
a qualified person.
Operating Modes
The gas control valve has two different operating modes: Standard and
Vacation. The Standard mode allows you to adjust the water temperature to your
desired setting. The Vacation (VAC) mode sets the thermostat at approximately
55°F and is recommended when not using hot water for an extended period of
time. The VAC setting also reduces energy losses and keeps the tank from
freezing during cold weather but can cause a Hydrogen gas build up. See
caution on page 6.
No Hot Water
Use the following step-by-step plan as a guide to help determine why you have
no hot water:
1 Check the Status Light
The Status Light on the gas control valve flashes once every four seconds when
there are no problems and there is no call for heat.
Figure 36 -Status light.
If the Status Light is flashing once every four seconds and you have no hot
water, make sure the gas control knob is set to HOT. If the Status Light
flashes a different pattern than is described above, refer to “LDO Module –
Status Light Code” on page 30.
If the Status Light is not flashing, go to step 2.
Status Light is Not Flashing
If the status light on the gas control valve does not flash, the system may be
locked out. Refer to “Status Light Troubleshooting Flowchart” on page 30. Be
sure to read the notes at the top of
that flowchart.
Insufficient Hot Water or Slow Hot Water Recovery
WARNING! Because of the increased risk from scalding, if you set the water
heater’s gas control knob higher than 120°F, install Thermostatic Mixing
Valves at each point-of-use. Due to the increased risk of scalding, do not set
the temperature of the Thermostatic Mixing Valves above 120°F.
If the hot water is simply not warm enough, there are several possible causes:
· Faulty Thermostatic Mixing Valve in a faucet or shower control (check other
faucets in the house for hot water).
· Water heater’s capacity too small (or usage too high).
· Reversed plumbing connections or melted dip tube (usually found soon after
new installation).
· Plumbing leak.
· Sediment or lime build up in the bottom of the tank.
Thermostatic Mixing Valves. If the hot water is simply not warm enough, make
sure the faucet you are checking doesn’t have a defective Thermostatic Mixing
Valve. Many shower controls now have built-in mixing valves. If these devices
fail, they can reduce the amount of hot water the shower or faucet delivers
even though there is plenty of hot water in the tank. Always check the water
temperature at several faucets to make sure the problem is not in a faucet or
shower control.
Undersized Water Heater. If your water heater runs out of hot water quickly,
it may be too small for your needs. If the water heater is old, consider
replacing it with a larger model. If the water heater is in good condition,
you may be able to meet your family’s hot water needs with the existing water
heater by installing Thermostatic Mixing Valves at each point-of-use and then
turning the gas control knob to a higher setting.
You can also reduce your home’s hot water needs by washing clothes in cold
water, installing flow restrictors on shower heads, repairing leaky faucets,
and taking other conservation steps.
Reversed Connections or Melted Dip Tube. Check the hot and cold water
connections and make sure your home’s hot water pipe is connected to the hot
water outlet on the water heater. Usually, reversed connections are found soon
after the installation of a new unit. If copper pipes were soldered while they
were attached to the water heater, the dip tube may have melted. The dip tube
is a long, plastic tube inside the tank attached to the cold water inlet. If
the dip tube has melted, it can be replaced by removing the cold water inlet
connection, removing the old dip tube and installing a new one.
Plumbing Leak. Even a small leak in the hot water side of the home’s
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 25
plumbing system can make it appear that the water heater is producing little
to no hot water. In this case, the burner will be on all or almost all the
time, yet you will have very little hot water. Locate and repair the leak.
Sediment or Lime in Tank. With an existing water heater, if you have some hot
water but not as much as you’re used to, there may be a build up of sediment
or lime on the bottom of the tank. Sediment or lime build up can reduce the
efficiency of your water heater. Heavy deposits can damage the water heater.
See the Maintenance section for steps on draining and flushing the water
heater.
Temperature Too High
Adjust the thermostat on the water heater to a lower setting. Install or
adjust Thermostatic Mixing Valves for each point-of-use (see the valve
manufacturer’s instructions).
Low Water Pressure
Check both the cold and hot water at a sink to determine if the lower pressure
is only on the hot water side. If both hot and cold faucets have low pressure,
call your local water utility. If the low pressure is only on the hot water
side, the primary causes are:
· Melted heat traps or dip tube. Soldering copper pipes while they are
connected to the water heater can melt the heat traps inside the hot and cold
water connections or the dip tube (cold water side). Melted heat traps or a
melted dip tube can restrict the flow of hot water. If that’s the case,
replace the heat traps or dip tube.
· Partially closed supply valve. Open the water heater’s supply valve fully.
Drips from T &P Relief Valve Discharge Pipe
A small amount of water dripping from the Temperature and Pressure (T&P)
Relief Valve usually means the home’s water pressure is too high and/or you
need a Thermal Expansion Tank. See Step 1 in the Installation section of this
manual for more information.
A large amount of hot water coming from the T&P discharge pipe may be due to
the tank overheating. If the T&P relief valve is discharging large amounts of
very hot water, turn the gas supply valve off and call a qualified person.
WARNING! Do not cap or plug the T&P Relief Valve or discharge pipe, and
do not operate the water heater without a functioning T&P Relief Valve–this
could cause an explosion.
Water Pressure too High. High water pressure can cause the T&P Relief Valve to
drip. Install a Pressure Reducing Valve (PRV) on the main cold water supply
line. Adjust the PRV to between 50 and 60 psi.
Thermal Expansion Tank. Install a Thermal Expansion Tank. If a Thermal
Expansion Tank is already installed and the T&P Relief Valve discharge pipe
drips, the home’s water pressure may be too high or the
Thermal Expansion Tank may be defective. Refer to the instructions that came
with the Thermal Expansion Tank for more information.
Debris. In rare cases, debris can stick inside the T&P Relief Valve preventing
the valve from sealing fully. In that case, the T&P Relief Valve discharge
pipe will drip. You may be able to clear debris from the T&P Relief Valve by
manually operating the valve, allowing small quantities of water to flush out
the debris. See the label on the T&P Relief Valve for instructions.
26 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
WARNING! When manually operating the temperature-pressure relief valve, make sure that no one is in front of or around the discharge outlet. The water may be extremely hot and could cause severe burns. Also ensure that the water discharge will not cause property damage. If the water pressure is between 50 and 60 psi, a Thermal Expansion Tank is installed and properly pressurized, and the valve has been cleared of any debris, and it still drips, the valve may be broken–have a qualified person replace the T&P Relief Valve.
Water Odor
Harmless bacteria normally present in tap water can multiply in water heaters
and give off a “rotten egg” smell. Although eliminating the bacteria that
causes “smelly water” is the only sure treatment, in some cases, the standard
anode rod that came with your water heater can be replaced with a special zinc
anode rod which may help reduce or eliminate the odor. Contact a qualified
person.
NOTICE: To protect the tank, an anode rod must be installed in the water
heater at all times or the warranty is void.
In cases where the “rotten egg” smell is very strong, you could increase the
tank temperature to 140°F in order to reduce bacterial growth in the tank.
WARNING! Because higher temperatures increase the risk of scalding, if you set
the thermostat(s) higher than 120°F, Thermostatic Mixing Valves at each point-
of-use are particularly important.
NOTICE: · These codes apply to the gas control valve. The location of the gas
control valve is shown on page 2.
· Refer to the following pages for detailed troubleshooting procedures.
LED FLASH SEQUENCE
No Flash
Short flash once every four second “Heartbeat”, alternates bright/dim One
Flash, three second pause Two Flash, three second pause Three Flash, three
second pause Four Flash, three second pause Five Flash, three second pause
Six-One Flash, three second pause Six-Two Flash, three second pause Six-Three
Flash, three second pause Six-Four Flash, three second pause Seven Flash,
three second pause Eight-One Flash, three second pause Eight-Two Flash, three
second pause Eight-Three Flash, three second pause Eight-Four Flash, three
second pause
- Soft Lockout – 20 minute wait before returning to normal mode.
CONTROL STATUS
Lock out. (Check the status light on the LDO module and refer to the LDO
Status Light Troubleshooting Flowchart on page 30. The location of the LDO
module is shown on page 2.) IDLE (No call for heat, no fault conditions) Call
for Heat (No fault conditions) Low Flame Signal (control continues to operate)
End Switch Failed Closed
End Switch Failed Open
ECO Limit Lockout (Overheat Failure)
Flame Out of Sequence Soft Lockout – Retry Limit – Failed TFI (Trial for
Ignition) Soft Lockout – Recycle Limit – Flame Lost – END Switch Fails Soft
Lockout – Recycle Limit – Flame Lost Soft Lockout – Flame out of Sequence
Sensed Flammable Vapor Sensor (FVS) Lockout
Flammable Vapor Sensor (FVS) Fault Detected Temperature Sensor Fault Detected
(No Light) Electronic Fault Detected
Gas Control Valve/Thermostat Fault Detected
EXAMPLE: An “Eight-Four Flash” will show eight flashes, then four flashes, followed by a three second pause. The pattern will then repeat.
TROUBLESHOOTING
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 27
STATUS LIGHT TROUBLESHOOTING FLOWCHART
Gas Control Valve/Thermostat – Status Light Code
LED FLASH SEQUENCE
No Flash
GAS CONTROL VALVE STATUS
Lock out
Short flash once every four second
“Heartbeat”, alternates bright/dim One Flash, three second pause
IDLE (No call for heat, no fault conditions)
Call for Heat (No fault conditions)
Low Flame Signal (control continues to operate)
Two Flash, three second pause
End Switch Failed Closed
Three Flash, three second pause End Switch Failed Open
Four Flash, three second pause
ECO Limit Lockout
Five Flash, three second pause
Flame Out of Sequence
CORRECTIVE ACTION
Check the status light on the LDO module and refer to the LDO Status Light
Troubleshooting Flowchart on page 30. The location of the LDO module is shown
on page 2.
Turn the power switch on the gas control valve to the “OFF” position and
unplug the power cord from the power outlet.
1. Check the incoming gas line pressure to ensure adequate supply to the
water heater. If incoming gas supply pressure is adequate, proceed to step 2.
2. Check all wiring connections and ensure all harness and wire connections
are seated firmly and provide proper electrical contact. If no connection
problems are found, proceed to step 3. Firmly seat any loose connections
found. If any connections are found to be damaged, consult the replacement
parts list for the appropriate replacement. After any connection problems are
fixed, restart the water heater by following the lighting instructions on page
23. If the problem persists, proceed to step 3.
3. Check the condition of the base ring filter and flame arrestor. If they
are clogged, follow the instructions for cleaning on page 36. If parts are not
clogged, proceed to step 4. After cleaning, follow the instructions for
lighting on page 23. If problem persists, proceed to step 4.
4. Follow the instructions on page 35 to remove the burner assembly. Once the
burner assembly has been removed, inspect the manifold tube and burner for any
obstructions. If any clogs or obstructions are present, clear them. Inspect
the pilot assembly’s electrode/ flame sense rod for corrosion buildup,
degradation, or damage. If there is evidence of any damage to the
electrode/flame sense rod, replace the igniter/pilot assembly. Follow the
directions on page 35 to re-install the burner assembly into the combustion
chamber. Follow the instructions for lighting on page 23. If the problem
persists, contact a certified service representative.
Look at the top of water heater to see if the damper is open (Figure 29, page
21). If the damper is open, ensure there is no obstruction that would prevent
the damper from closing. If there are any obstructions, turn the power switch
on the gas valve to the “OFF” position, then remove the obstruction. If the
damper closes, turn the power switch on the gas valve to the “ON” position. If
there are no obstructions present, turn the power switch on the gas valve to
the “OFF” position. Observe the damper to see if the damper closes. If the
damper does not close, unplug the power cord from the power outlet and proceed
to step 1. If the damper closes turn the power switch on the gas valve to the
“ON” position.
1. Check all wiring connections to ensure all harness and wire connections
are seated firmly and provide proper electrical contact. If no connection
problems are found, replace the damper. Firmly seat any loose connections
found. If any connections are found to be damaged, consult the replacement
parts list on for the appropriate replacement. After any connection problems
are fixed, restart the water heater by following the lighting instructions on
page 23. If the problem persists, replace the damper.
Turn the power switch on the gas control valve to the “OFF” position and
unplug the power cord from the power outlet.
1. Follow the lighting instructions on page 24. Observe the damper during
initial startup. If there is a call for heat and the damper opens, allow the
unit to continue to perform and monitor any change in status. If there is a
call for heat and the damper does not open, procede to step 2.
2. Check all wiring connections to insure all harness and wire connections
are seated firmly and provide proper electrical contact.If no connection
problems are found replace the damper.Firmly seat any loose connections found.
If any connections are found to be damaged, consult the replacement parts list
on page 39. After any connection problems are fixed, restart the water heater
by following the lighting instructions on page 24. If the problem persists,
replace the damper.
1. Turn the power switch on the gas control valve to the “OFF” position, wait
10-20 seconds, then turn the power switch on the gas control valve to the “ON”
position. If the problem persists, replace the gas control valve. (See page
34.)
1. Turn the power switch on the gas control valve to the “OFF” position. Wait
10 minutes, then follow the lighting instructions on page 23. If the problem
persists, replace the gas control valve. (See page 34.)Residential Standard
Gas Ultra Low Nox Water Heater Use and Care Guide
STATUS LIGHT TROUBLESHOOTING FLOWCHART (CONTINUED)
Gas Control Valve/Thermostat – Status Light Code
LED FLASH SEQUENCE
Six-One Flash, three second pause
Six-Two Flash, three second pause Six-Three Flash, three second pause
Six-Four Flash, three second pause
CONTROL STATUS
Soft Lockout – Retry Limit Failed TFI (Trial for Ignition)
Soft Lockout – Recycle Limit – Flame Lost – END Switch Fails
Soft Lockout* – Recycle Limit – Flame Lost
- Soft Lockout – 20 minute wait before returning to normal mode. Soft Lockout* – Flame out of Sequence Sensed
CORRECTIVE ACTION
Turn the power switch on the gas valve to the OFF position. Unplug the water
heater from the wall outlet. Plug the power cord back in, then follow the
lighting instructions on page 23. If that does not work, turn the power switch
on the gas control valve to the “OFF” position, unplug the power cord from the
power outlet, then follow the steps below.
1. Check the incoming gas line pressure to ensure adequate supply to the
water heater. If incoming gas supply pressure is adequate, proceed to step 2.
2. Check all wiring connections and ensure all harness and wire connections
are seated firmly and provide proper electrical contact. If no connection
problems are found, proceed to step 3. Firmly seat any loose connections
found. If any connections are found to be damaged, consult the replacement
parts list for the appropriate replacement. After any connection problems are
fixed, restart the water heater by following the lighting instructions on page
23. If the problem persists, proceed to step 3.
3. Check the condition of the base ring filter and flame arrestor. If they
are clogged, follow the instructions for cleaning on page 36. If parts are not
clogged, proceed to step 4. After cleaning, follow the instructions for
lighting on page 23. If problem persists, proceed to step 4.
4. Follow the instructions on page 35 to remove the burner assembly. Once the
burner assembly has been removed, inspect the manifold tube and burner for any
obstructions. If any clogs or obstructions are present, clear them. Inspect
the pilot assembly’s electrode/ flame sense rod for corrosion buildup,
degradation, or damage. If there is evidence of any damage to the
electrode/flame sense rod, replace the igniter/pilot assembly. Follow the
directions on page 35 to re-install the burner assembly into the combustion
chamber. Follow the instructions for lighting on page 23. If the problem
persists, contact a qualified service representative.
Turn the power switch on the gas control valve to the “OFF” position and
unplug the power cord from the power outlet.
1. Check all wiring connections to ensure all harness and wire connections
are seated firmly and provide proper electrical contact. If no connection
problems are found, replace the damper. Firmly seat any loose connections
found. If any connections are found to be damaged, consult the replacement
parts list for the appropriate replacement. After any connection problems are
fixed, restart the water heater by following the lighting instructions on page
23. If the problem persists, replace the damper.
Turn the power switch on the gas control valve to the “OFF” position and
unplug the power cord from the power outlet.
1. Check the incoming gas line pressure to ensure adequate supply to the
water heater. If incoming gas supply pressure is adequate, proceed to step 2.
2. Check all wiring connections and ensure all harness and wire connections
are seated firmly and provide proper electrical contact. If no connection
problems are found, proceed to step 3. Firmly seat any loose connections
found. If any connections are found to be damaged, consult the replacement
parts list for the appropriate replacement. After any connection problems are
fixed, restart the water heater by following the lighting instructions on page
23. If the problem persists, proceed to step 3.
3. Check condition of the base ring filter and flame arrestor. If they are
clogged, follow the instructions for cleaning on page 36. If the parts are not
clogged, proceed to step 4. After cleaning, follow instructions for lighting
on page 23. If the problem persists, proceed to step 4.
4. Follow the instructions on page 35 to remove the burner assembly. Once the
burner assembly has been removed, inspect the manifold tube and burner for any
obstructions. If any clogs or obstructions are present, clear them. Inspect
the pilot assembly’s electrode/ flame sense rod for corrosion buildup,
degradation, or damage. If there is evidence of any damage to the
electrode/flame sense rod, replace the igniter/pilot assembly. Follow the
directions on page 35 to re-install the burner assembly into the combustion
chamber. Follow the instructions for lighting on page 23. If the problem
persists, contact a qualified service representative.
Turn the power switch on the gas control valve to the “OFF” position and
unplug the power cord from the power outlet. Wait 10 minutes, then follow the
lighting instructions on page 23. If the problem persists, replace the gas
control valve. (See page 34.)
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 29
STATUS LIGHT TROUBLESHOOTING FLOWCHART (CONTINUED)
Gas Control Valve/Thermostat – Status Light Code
LED FLASH SEQUENCE
CONTROL STATUS
CORRECTIVE ACTION
Seven Flash, three second pause
Flammable Vapor Sensor (FVS) Lockout
1. Do not touch any electrical switch, do not use any phone in the building,
and do not try to light any appliance.
2. Smell around the water heater to ensure there are no gas leaks at the gas
control valve or in the supply gas line or for any other type of flammable
vapors in the area.
3. Carefully inspect the area surrounding the water heater for any substances
such as gasoline, paint, paint thinners, varnish, or cleaners that could emit
flammable vapors. Remove anything that can potentially emit flammable vapors
from the area and store it properly in a different location.
4. Contact a qualified service representative for inspection and/or
replacement of the FV sensor.
Eight-One Flash, three second pause
Flammable Vapor Sensor (FVS) Fault Turn the power switch on the gas control valve to the “OFF” position, wait 10-20 seconds, then
Detected
turn the power switch on the gas control valve to the “ON” position. If the problem persists,
replace the gas valve.
Eight-Two Flash, three second pause
Temperature Sensor Fault Detected
Turn the power switch on the gas control valve to the “OFF” position, wait 10-20 seconds, then turn the power switch on the gas control valve to the “ON” position. If the problem persists, replace the gas valve.
Eight-Three Flash, three second pause
Electronic Fault Detected
Turn the power switch on the gas control valve to the “OFF” position, wait 10-20 seconds, then turn the power switch on the gas control valve to the “ON” position. If the problem persists, replace the gas valve.
Eight-Four Flash, three second pause
Gas Control Valve/Thermostat Fault Detected
Turn the power switch on the gas control valve to the “OFF” position, wait 10-20 seconds, then turn the power switch on the gas control valve to the “ON” position. If the problem persists, replace the gas valve.
- Soft Lockout – 20 minute wait before returning to normal mode.
STATUS LIGHT TROUBLESHOOTING FLOWCHART
LDO Module – Status Light Code
NOTICE: · These codes apply to the LDO module. See page 2 for the location of
the LDO module. · If the status light on the gas control valve is not
flashing, check the status light on the LDO module and refer to the table
below.
Status Normal Operation Burner Failure
Lint Build-Up Detected
Chamber Sensor Failure
LDO Status
1 sec. 4 sec. 1 sec.
4 sec.
Gas Control Valve Status
Heart Beat None Needed
Corrective Action
No Light No Light No Light
· Replace Burner · Press and hold reset button on LDO module for 3 sec-
onds to clear the fault code.
· Remove Lint and Dust Build-up. · Ensure gas supply pressure is correct. ·
Requires main power to be cycled in order to clear fault
code.
· Ensure sensor is connected properly to LDO module. · Replace Chamber Sensor.
See Figure 50. · Fault code clears immediately when condition clears.
TROUBLESHOOTING
30 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
SEQUENCE OF OPERATIONS CHART
Apply Power to Appliance.
Is there a Call for Heat.
Y
Is Damper
N
Closed?
Will not attempt to light. 2 flash error code.
Damper Energizes.
Is Damper
N
Open?
Gas Valve attempts to open damper for 30 seconds, displays 3 flash error code, and then waits 2 minutes before attempting to open damper again.
Pilot Valve Energizes
Does Pilot
N
Valve Open?
Will not light. 8-4 flash error code.
Spark Electrode is Energized
Is Pilot Flame Sensed Within 1.5 min. ?
N
Will not light. 8-4 flash
error code.
Main Valve Energized
Does Main Valve Open?
N
Will not light. 8-4 flash
error code.
Is Main Flame Sensed?
N
Will not light. 8-4 flash
error code.
Is Demand for Heat Satisfied?
Water heater will continue to
N
operate normally until
demand is satisfied.
Pilot & Main Valve De-Energize.
Is Flame Sensed?
Y
Wait for flame lost, 5 flash
error code.
Damper Energizes and Closes.
Damper closes, displays 6-4 Flash Error Code, and gas control valve goes into 20 minute lockout.
TROUBLESHOOTING
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 31
MAINTENANCE
Routine Maintenance
Routine maintenance will help your water heater last longer and work better.
If you can’t perform these routine maintenance tasks yourself, contact a
qualified person.
Draining and Flushing the Water Heater
Tap water contains minerals that can form sediment in the bottom of the tank.
The amount of sediment formed depends on the hardness of your tap water, the
temperature settings, and other variables. We recommend draining and flushing
the water heater after the first six months of operation to determine the
amount of sediment build up. If there is little sediment, drain and flush the
tank annually. If there is a lot of sediment, drain and flush the tank more
often. Draining sediment extends the life of the water heater.
To Drain and Flush the Tank:
1 Turn the power switch on the gas control valve to the OFF position.
Figure 37 -Turn gas control/temperature knob OFF.
2 Turn the manual gas valve for the water heater’s supply line OFF.
3 Open a hot water faucet and let the hot water run until it is cool (This may
take 10 minutes or longer).
Figure 38 -Let the hot water run until it is cool.
WARNING! Be sure the water runs cool before draining the tank to reduce the
risk of scalding.
4 Connect a garden hose to the drain valve and place the other end of the hose
in a drain, outside, or in buckets. Note that sediment in the bottom of the
tank may clog the valve and prevent it from draining. If you can’t get the
tank to drain, contact a qualified person.
5 Turn the cold water supply valve OFF.
6 Open the drain valve on the water heater.
Figure 39 -Draining the water heater.
7 Also open a hot water faucet to help the water in the tank drain faster.
8 Remove and inspect the anode rod and replace if depleted. The anode rod
requires a 1-1/16″ socket.
Figure 40 -Anode rods from new (top) to partially depleted (middle) to fully
depleted stage (bottom).
Anode Rod. The anode rod is a sacrificial metal rod that helps avoid corrosion
and premature failure (leaks) in the tank. The anode rod is a consumable item.
Inspect the anode rod after the first six months of operation when you drain
and flush the tank. Replace the anode rod if it is substantially worn out or
depleted. Thereafter, inspect the anode rod annually or more frequently if
needed. If you use a water softener, your anode rod will deplete faster than
normal. Inspect the anode rod more frequently, replacing the anode rod if it
is depleted. Obtain a new anode rod from Lowe’s® or have a qualified person
replace it. (Anode rods are a consumable item and are not covered under
warranty).
9 If a large amount of sediment was present when the tank was drained, flush
the tank by opening the cold water supply valve and letting the water run
until no more sediment drains from the tank. Close
MAINTENANCE
32 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
MAINTENANCE
the drain valve when you are done.
10 Refill the tank by opening the cold water supply valve. Make sure a hot
water faucet is open and the drain valve is closed. Allow a hot water faucet
to run full for at least three minutes to make sure the tank has all the air
removed and is completely full of water. Once you are certain the tank is
completely full of water, close the hot water faucet.
11 Put the water heater back into operation by following the lighting
instructions on page 23. Adjust the gas control knob to the desired
temperature. It may take an hour or more for the tank of cold water to heat
up.
Visual Inspection
On an annual basis, visually inspect the venting and air supply system, piping
systems, main burner, pilot burner, and the air filter.
Check the water heater for the following:
· Obstructions, damage, or deterioration in the venting system. Make sure the
ventilation and combustion air supplies are not obstructed. Check the air
filter for dust or other debris and clean if needed.
· Build up of soot and carbon on the main burner and pilot burner. The burner
may be cleaned with soap and hot water.
· Inspect the burner flames through the viewport and compare them to Figure
41. The flames should be very small with a blue haze and small amount of
yellow or orange at the edges. After several minutes of operation, the burner
screen may glow red. If large flames are observed at any time, shut-off the
unit and call a qualified person.
Correct flame soft blue
Figure 41 – Burner Flames
· Leaking or damaged water and gas piping.
· Remove any flammable, corrosive or combustible materials near the water
heater.
If you lack the necessary skills required to properly perform this visual
inspection or if the burner needs to be cleaned, get help from a qualified
person.
T&P Relief Valve Maintenance
Figure 42 -T&P Relief Valve.
Read and follow the operating and annual maintenance instructions provided by
the manufacturer of the T&P Relief Valve (yellow label attached to T&P Relief
Valve). Minerals in the water can form deposits that cause the valve to stick
or create blocked passages, making the T&P Relief Valve inoperative. Follow
these guidelines: · At least annually, operate the T&P
Relief Valve manually to ensure the waterways are clear and the valve
mechanism moves freely (above). Before operating the valve manually, check
that it will discharge in a place for secure disposal. WARNING! Hot water will
be released. Before operating the T&P relief valve manually, check that it
will discharge in a safe place. If water does not flow freely from the end of
the discharge pipe, turn the gas control knob to the OFF position and call a
qualified person to determine the cause.
· At least every five years, have a qualified person inspect the T&P Relief
Valve and discharge pipe. Damage caused by corrosive water conditions, mineral
deposits, or other problems can only be determined when a qualified person
removes and inspects the valve and its components.
A dripping T&P Relief Valve is usually caused by the home’s water pressure
being too high or the lack of a Thermal Expansion Tank. If your T&P Relief
Valve drips, see page 26. A T&P relief valve that has been allowed to drip for
an appreciable period of time should be inspected for mineral buildup. See T&P
relief valve tag for more information.
Inspect and Clean the Air Filter
Figure 43 -Clean air filter periodically.
An air filter is installed around the base of your water heater. At least
annually, inspect the air filter and check for a build-up of dust or debris.
If it needs to be cleaned, turn off the water heater and allow it to cool for
ten minutes before cleaning. Vacuum the filter to remove any dust or debris.
If an oily residue is present on the filter, wash it in soap and water, then
dry the filter. NOTICE: If you are unable to inspect or clean the filter,
follow the “Cleaning the Combustion Chamber and Flame-arrestor” instructions
on page 36.
MAINTENANCE
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 33
Removing and Replacing the Gas Control Valve/Thermostat
IMPORTANT: The gas control valve/ thermostat is a standard valve. Removing the
Gas Control Valve/ Thermostat:
1 Turn the gas control valve switch to the “OFF” position.
Figure 44 -Turn the gas control valve off.
2 Turn off the gas at the manual shut-off valve on the gas supply pipe.
Figure 45 – Gas valve in “off” position.
3 Drain the water heater. Refer to “Draining and Flushing the Water Heater”
and follow the procedure. (See page 32.)
4 Disconnect the following items from the gas control valve/thermostat: A Igniter wire B Wiring harness C FV sensor wires D Pilot tube (7/16″ wrench) E Manifold tube (3/4″ wrench)
A Igniter Wire
B Wiring Harness (from black box and hole in jacket)
E Pilot D Tube
Manifold Tube
c FV Sensor
(from bottom of heater)
Figure 46 – Gas valve connections.
5 Disconnect the ground joint union in the gas piping. Disconnect the remaining pipe from the gas control valve/ thermostat.
MANUAL GAS SHUT-OFF VALVE
GROUND JOINT UNION
Figure 47 – Ground joint union connection.
6 To remove the gas control valve/thermostat, thread a 4″ section of gas pipe
into the inlet and use it to turn the gas control valve/thermostat
(counterclockwise).
Do not use pipe wrench or equivalent to grip body. Damage may result, causing
leaks. Do not insert any sharp objects into the inlet or outlet connections.
Damage to the gas control valve/ thermostat may result.
STATUS ON OFFigure 48 – Gas control/valve with 4″ section of threaded gas
pipe.
Replacing the Gas Control Valve/ Thermostat: · Be sure to use approved Teflon®
tape or pipe joint compound on the gas piping connections and fitting on the
back of the gas control valve that screws into tank. · Be sure to remove the
pilot ferrule nut from the new gas control valve/thermostat.
Replace the gas control valve/thermostat by reassembling in reverse order.
When replacing the gas control valve/ thermostat, thread a 4″ section of gas
pipe into the inlet and use it to turn the gas control valve/thermostat
(clockwise). DO NOT OVER TIGHTEN.
Damage may result.
MAINTENANCE
34 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
MAINTENANCE
Figure 49 – Gas valve in “on” position.
· Be sure tank is completely filled with water before lighting and activating
the water heater. Follow the “Lighting Instructions” on page 23.
· Turn the gas supply on and check for leaks. Test the water heater with the
main burner on by brushing on an approved noncorrosive leak detection
solution. Bubbles forming indicate a leak. Correct any leak found.
· If additional information is required, contact the Service Department at:
1-877-817-6750 .
Removing and Replacing the Manifold/Burner Assembly
Removing the Manifold/Burner Assembly
Move the ON/OFF switch on
1 the gas control valve/thermo-
stat to the “OFF” position to turn off the water heater (Figure 44).
2 Turn off the gas to the water heater at the manual gas shut-off valve
(Figure 45).
3 Remove the outer door.
Remove the manifold screws
4 (1/4″ nut driver) securing the
manifold door to the combustion chamber (Figure 50).
LDO Module
Gas Control Valve/ Thermostat
Pilot Tube Viewport FV Sensor
Temperature Sensor Wire Connection
Wiring Harness
Manifold Tube
Temperature Sensor
Manifold Door
Manifold Screw (2 or 4)
Manifold Component Block
Figure 50 – Front view of water heater with outer door removed.
Go to the gas control valve/
5 thermostat and disconnect
the pilot tube (7/16″ wrench), igniter wire, and manifold tube (3/4″ wrench).
Disconnect the FV sensor and wiring harness.
6 Disconnect the temperature sensor wires from the LDO module.
Grasp the manifold tube and
7 push down slightly to free the
manifold and pilot tube.
Carefully remove the burner
8 door assembly from the
burner compartment. To reinstall it, see “Replacing the Manifold/Burner
Assembly” NOTICE: Be sure not to damage
internal parts.
Replacing the Manifold/Burner Assembly
· Remove any fiberglass between gasket and combustion chamber.
· Replace viewport if glass is missing or damaged.
· Replace the manifold component block if it is missing or removed.
· Replace door gasket if it is damaged.
1 Check the door gasket for damage or embedded debris prior to installation.
2 Inspect the viewport for damage and replace as required.
3 Insert the burner assembly into the burner compartment, making sure that the
burner assembly sits firmly against the burner bracket and spring (if
equipped) inside the combustion chamber. See Figure 51.
Burner Spring Door Gasket
Burner Bracket
Base Ring Filter Two Screw Burner Chamber
Door Gasket
Explosion Risk
WARNING! Failure to follow these instructions can result in serious injury or
death from explosion, fire or carbon monoxide poisoning.
· Tighten the manifold door screws securely.
Base Ring Filter Four Screw Burner Chamber
Figure 51 – Installing the burner assembly.
4 Inspect the door gasket and make sure there is no fiberglass insulation
between the gasket and the combustion chamber.
5 Replace the screws which secure the burner assembly to the combustion
chamber and tighten securely. There should be no space between the gasket part
of the burner door and combustion chamber. WARNING! Do not operate the water
heater if the door gasket does not create a seal between the burner door and
the combustion chamber.
6 Reconnect the manifold tubing (3/4″ wrench), pilot tubing (7/16″ wrench) to
the gas control valve/thermostat. Also reconnect the FV sensor wires, wiring
harness, and igniter wire. (See Figure 46 for the correct position of each
connection.) Do not cross-thread or apply any thread sealant to the fittings.
Reconnect the temperature
7 sensor wires to the LDO
module.
Cleaning the Combustion Chamber and Flame-arrestor
See also “Inspect and Clean the Air Filter” on page 33.
1 Follow the steps in “Removing the Manifold/Burner Assembly” on page 35.
2 Use a vacuum cleaner/shop vac to remove all loose debris in the combustion
chamber (Figure 52). Use compressed air to clear any dust or debris that may
have accumulated in the flame-arrestor.
3 Follow the steps in “Replacing the Manifold/Burner Assembly” on page 35.
COMBUSTION CHAMBER
8 Follow the “Lighting Instructions” on page 23.
9 Check for leaks with the main burner on by brushing on an approved
noncorrosive leak detection solution. Bubbles forming indicate a leak. Correct
any leak found. IMPORTANT: All leaks must be fixed immediately.
10 Replace the outer door.
When ordering repair parts, always give the following information:
1. Model, serial, and product number 2. Type of gas 3. Item number 4. Parts
description
Repair Parts List
Item No.
Parts Description
1 DRAFT HOOD
2 FLUE DAMPER
3 FLUE BAFFLE
4 HEAT TRAP/DIP TUBE COMBINATION
5 HEAT TRAP/ANODE ROD COMBINATION
6 TEMPERATURE & PRESSURE RELIEF VALVE (LOCATED ON SIDE OR TOP)
7 DRAIN VALVE
8 GAS CONTROL VALVE/THERMOSTAT
9 LDO ASSEMBLY KIT
10 PILOT ASSEMBLY KIT
11 BURNER ASSEMBLY
12* MANIFOLD COMPONENT BLOCK
13* MANIFOLD DOOR GASKET
14* VIEWPORT ASSEMBLY
15 OUTER DOOR
- Not shown.
6
1
5
NOTE: Damper orientation may vary
2
6
9 8 10
7 11 15
4 3
Listed Parts Kits and Illustrations
Item 10: Pilot Assembly kit, which contains the pilot, thermopile, and
retainer clip (Natural Gas) Item 11: Burner Assembly (Natural Gas) Item 12:
Contains manifold component block and retainer clip Item 13: Contains manifold
door gasket Item 14: Contains viewport
Item #10
Item #11
Item #12
Item #13
Item #14
REPAIR PARTS
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 37
NOTES
38 · Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide
NOTES
NOTES
Residential Standard Gas Ultra Low Nox Water Heater Use and Care Guide · 39
NOTES
LOWE’S is a registered Trademark of LF, LLC. Copyright © 2023, A.O. Smith. All
Rights Reserved
Limited Warranty provided by Manufacturer.