A.O. Smith APW015DW Installation & Service Manual page 17

4
Adjustments
The control and the high limit are set at factory defaults. If
changes are required, the set point and high limit can be easily
changed. This is accomplished using the controls provided on
the temperature controller and the high limit switch contained
in the control box (see FIG. 4-5). These items can be viewed
on the front door of the control box.
Figure 4-5 Control Box - Front View
TEMPERATURE
CONTROLLER
When the power switch on the control box
NOTICE
is set to the ON position, it also energizes the
internal 24 VAC transformer in the control
box. This in turn provides 24 VAC power
to the control valve actuator, provided the
water temperature at the heater outlet is
below the high temperature limit setting.
Set point temperature adjustment
The set point temperature is adjusted using the controls and
displays provided on the temperature controller. These controls
and displays are illustrated and described in FIG. 4-6 and Table
4B on page 18. If necessary, set point temperature adjustment is
accomplished as follows:
1. Set the ON/OFF POWER switch on the right side to the ON
position. The temperature controller will initiate a self-
test for approximately 3 seconds. Following the self-test,
the top display will show the current outlet water temperature
of the heater above the current set point temperature stored
in memory.
Indirect Plate Water Heater Installation & Service Manual
(continued)
HIGH LIMIT
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2. Ensure that the temperature controller is set to AUTO
(automatic) Mode and the AUTO indicator is lit. If the
MAN indicator is lit, press the AUTO/MAN button to
toggle the mode setting.
3. If the lower display does not show the desired set point
temperature, press the p
change the display to the desired value.
4. Two seconds after the p
released, the display will blink to indicate that the
temperature controller (FIG. 4-6) has accepted and stored
the displayed value.
Figure 4-6 Temperature Controller
or arrow button to
q
or arrow button is
q
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