Temperature Regulation - A.O. Smith GPD-40 Instruction Manual

Due to the nature of the typical gas water heater, the water
temperature in certain situations may vary up to 30°F (16.7°C)
higher or lower at the point of use such as, bathtubs, showers,
sink, etc.
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
satisfi es your hot water needs. This will also provide the most
energy effi cient operation of the water heater.
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 infi rm, or physically/mentally
disabled. If anyone using hot water in your home fi ts 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 satisfi es 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, see Figure 31.
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 should be installed over the thermostat to prevent
tampering.
The water temperature setting was factory set at the lowest
temperature; Pressing the "COOLER"
temperature and pressing the "HOTTER"
the temperature.
Setting the water heater temperature at 120°F (49°C) (Approx.
" " mark on temperature setting of gas control valve/thermostat)
will reduce the risk of scalds. Some states require settings at
specifi c lower temperatures.

TEMPERATURE REGULATION

button decreases
button increases
To avoid any unintentional changes in water temperature settings,
the gas control valve/thermostat 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 31. 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.
GAS CONTROL VALVE/THERMOSTAT - FRONT VIEW
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
Time to Produce 2nd and
Display
3rd Degree Burns on
A B C
Adult Skin
About 1/2 second
About 1-1/2 seconds
Less than 5 seconds
About 30 seconds
More than 5 minutes
- - - - - - - - - - - - -
FIGURE 31.