Temperature Regulation - A.O. Smith GPS-75 Instruction Manual

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.
It is recommended that lower water temperatures be used to avoid
the risk of scalding. It is further recommended, in all cases, that the
water temperature be set for the lowest temperature which satisfies
your hot water needs. This will also provide the most energy efficient
operation of the water heater.
Figure 20 shows the approximate water temperatures produced at
various thermostat settings. 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 (17°C). If you experience
this type of use you should consider using lower temperature settings
to reduce scald hazards.
Valves for reducing the point-of-use temperature by mixing cold and
hot water are available, see Figure 2. Also available are inexpensive
devices that attach to faucets to limit hot water temperatures. Contact
a licensed plumber or the local plumbing authority.
HOT 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, should be used at the hot water taps used by these people or
at the water heater. Mixing valves are available at plumbing supply
or hardware stores, 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 Figure 20.
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.
The water heater should be located in an area where the general
public does not have access. If a suitable area is not available, a cover

teMperature reGulatIon

should be installed over the thermostat to prevent tampering.
The water temperature setting was factory set at the lowest temperature;
Pressing the "COOLER"
pressing the "HOTTER"
Setting the water heater temperature at 120°F (49°C) (Approx. "
" mark on temperature setting of gas valve) will reduce the
risks of scalds. Some states require settings at specific lower
temperatures.
To avoid any unintentional changes in water temperature settings, the
control has a tamper resistant feature for changing the temperature
setting. To change the temperature setting follow these instructions:
1. "Wake Up" the temperature indicators by holding down both
"COOLER" and "HOTTER" temperature adjustment buttons at
the same time for one second, see Figure 20. One or two of the
temperature indicators will light up. These indicators will only
remain on for 30 seconds if no further buttons are pressed. After
30 seconds the control will go back to "Sleep" mode.
2. Release both of the temperature adjustment buttons.
a. To decrease the temperature press and release the "COOLER"
button until the desired setting is reached.
b. To increase the temperature press and release the "HOTTER"
button until the desired setting is reached.
NOTE: Holding down the button will not continue to lower or raise
the temperature setting. The button must be pressed and released
for each temperature change desired.
Should overheating occur or the gas supply fail to shut off, turn off
the manual gas control valve to the appliance.
Temperature Setting
C-Flashing = approx. 160°F (71°C)
C = approx. 150°F (66°C)
B = approx. 140°F (60°C)
A = approx. 130°F (54°C)
= approx. 120°F (49°C)
WARM = approx. 80°F (27°C)
24
button decreases temperature and
button increases the temperature.
Time to Produce
Display 2nd and 3rd Degree
A B C Burns on Adult Skin
About 1/2 seconds
About 1-1/2 seconds
Less than 5 seconds
About 30 seconds
More than 5 minutes
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fIGure 20.