Temperature Regulation; For Your Information; Start Up Conditions; Draft Hood Operation - A.O. Smith Residential Gas Water Heaters Instruction Manual

Short repeated heating cycles caused by small hot water uses can
cause temperatures at the point of use to exceed the thermostat setting
by up to 30°F (16.7°C). If you experience this type of use you should
consider using lower temperature settings to reduce scald hazards.
Any water heater's intended purpose is to heat water. Hot water is
needed for cleansing, cleaning, and sanitizing (bodies, dishes, clothing).
Untempered hot water can present a scald hazard. Depending on the
time element, and the people involved (adults, children, elderly, infirm,
etc.) scalding may occur at different temperatures.
HOTTER WATER CAN SCALD: Water heaters are intended to produce
hot water. Water heated to a temperature which will satisfy space
heating, clothes washing, dish washing, and other sanitizing needs
can scald and permanently injure you upon contact. Some people are
more likely to be permanently injured by hot water than others. These
include the elderly, children, the infirm, or physically/mentally
handicapped. If anyone using hot water in your home fits into one of
these groups or if there is a local code or state law requiring a certain
temperature water at the hot water tap, then you must take special
precautions. In addition to using the lowest possible temperature setting
that satisfies your hot water needs, a means such as a mixing valve,
shall be used at the hot water taps used by these people or at the
water heater. Mixing valves are available at plumbing supply or
hardware stores, see Figure 2. Follow manufacturer's instructions for
installation of the valves. Before changing the factory setting on the
thermostat, read the "Temperature Regulation" section in this manual,
see Figures 15 and 16.

START UP CONDITIONS

DRAFT HOOD OPERATION

Check draft hood operation by performing a worst case depressurization
of the building. With all doors and windows closed, and with all air
handling equipment and exhaust fans operating such as furnaces, clothes
dryers, range hoods and bathroom fans, a match flame should still be
drawn into the draft hood of the water heater with its burner firing. If the
flame is not drawn toward the draft hood, shut off water heater and
make necessary air supply changes to correct.

CONDENSATION

Whenever the water heater is filled with cold water, some condensate
TEMPERA TEMPERATURE REGULA TEMPERA TURE REGULA TURE REGULATION TURE REGULA
TEMPERA TEMPERA TURE REGULA
FOR Y FOR YOUR INFORMA FOR Y OUR INFORMATION OUR INFORMA OUR INFORMA
FOR Y FOR Y OUR INFORMA
TION TION TION
TION
Never allow small children to use a hot water tap, or to draw their own
bath water. Never leave a child or handicapped person unattended in
a bathtub or shower.
NOTE: A water temperature range of 120°F-140°F (49°C-60°C) is
recommended by most dishwasher manufacturers.
The thermostat of this water heater has been factory set at its lowest
position (PILOT LIGHTING). It is adjustable and must be reset to the
desired temperature setting to reduce the risk of scald injury. The mark
( ) indicative of approximately 120°F (49°C) is preferred starting
point. Some States have a requirement for a lower setting.
Turn the water temperature dial clockwise (
temperature, or counterclockwise (
Should overheating occur or the gas supply fail to shut off, turn off the
manual gas control valve to the appliance.
Temperature
Settings
VERY HOT= approx. 160°F (71°C)
C = approx. 150°F (66
B = approx. 140°F (60°C)
A = approx. 130°F (54°C)
= approx. 120°F (49°C)
LOW = approx. 80°F (27°C)
TION TION TION
TION
will form while the burner is on. A water heater may appear to be leaking
when in fact the water is condensation. This usually happens when:
a. A new water heater is filled with cold water for the first time.
b. Burning gas produces water vapor in water heaters, particularly
high efficiency models where flue temperatures are lower.
c. Large amounts of hot water are used in a short time and the refill
water in the tank is very cold.
Moisture from the products of combustion condense on the cooler tank
surfaces and form drops of water which may fall onto the burner or
other hot surfaces to produce a "sizzling" or "frying" noise.
Excessive condensation can cause pilot outage due to water running
down the flue tube onto the main burner and putting out the pilot.
17
) to decrease the
) to increase the temperature.
FIGURE 15.
Time to Produce 2nd & 3rd
Degree Burns on Adult Skin
About 1/2 second
°C)
About 1-1/2 seconds
Less than 5 seconds
About 30 seconds
More than 5 minutes
- - - - - - - - - - - - - - - -
FIGURE 16.