A.O. Smith 12 40GPC T 100 - Manual (Page 17)

17
ADJUSTING THE TEMPERATURE ON THE
ELECTRONIC CONTROL DISPLAY
Adjusting the Temperature Set Point - The thermostat of this water heater has been factory set at its
lowest position. It is adjustable and must be reset to the desired temperature setting to reduce the risk of
scald injury. The electronic control display temperature should be set at approximately 120°F (49°C) and
this is the preferred starting point, see Figure 21 Some states have a requirement for a lower setting. If you
need hotter water, follow directions for temperature adjustment, but beware of the warnings in this section.
Pressing the “COOLER” button decreases temperature and pressing the “HOTTER” button increases
the temperature.
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. “Unlock” the temperature indicators by holding down both “COOLER” and “HOTTER” temperature
adjustment buttons at the same time for one second (See Figure 21). The temperature indicators will light
up and will only remain on for 30 seconds if no further buttons are pressed. After 30 seconds the control
will go back to “Lock” mode (“Lock” mode indicates a temperature setting is locked into the control
memory).
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: Should overheating occur or the gas supply fail to shut off, turn off the manual gas control valve to
the heater.
Water
Temperature
°F
Time for 1st
Degree Burn
(Less Severe Burns)
Time for Permanent Burns
2nd & 3rd Degree
(Most Severe Burns)
110 (normal shower temp.)
116 (pain threshold)
116 35 minutes 45 minutes
122 1 minute 5 minutes
131 5 seconds 25 seconds
140 2 seconds 5 seconds
149 1 second 2 seconds
154 instantaneous 1 second
(U.S. Government Memorandum, C.P.S.C., Peter L. Armstrong, Sept. 15,1978)
Figure 21.
Table 2
Gas Control Valve/Thermostat Settings
COOLER HOTTER
Electronic Control Display