Control System Operation; Heating Element Operation; Control System Features; Control System Navigation - A.O. Smith DSE-5 Instruction Manual

heatInG eleMent operatIon

fIGure 3.
Depending on tank size and how they were ordered from the factory
the water heaters covered in this manual may be equipped with 1
to 5 electric heating elements. The illustration here shows how the
heating elements are numbered for control purposes and how the
openings for each heating element are physically located on the
water heater's storage tank.
control options
The water heaters covered in this manual are factory ordered with 1
of 3 different heating element control options as follows:
On/Off Control: This is the only configuration available on models
equipped with a single heating element and the standard configuration
on models equipped with more than one element. All elements are
cycled on simultaneously with each call for heat, however there is
a one second delay between elements being energized to reduce
starting current. All elements are cycled off at the same time at the
end of each heating cycle.
Linear Sequencing: Only available on models equipped with
multiple heating elements. Elements are energized and de-energized
according to adjustable (1 to 20°F) Differential set points for each
element. Element Rotation - first element on is rotated with each
successive call for heat. First On/Last Off - the first heating element
energized at the beginning of a heating cycle is the last element
de-energized at the end of the heating cycle. Successive heating
cycles would progress as follows on a model equipped with 3 heating
elements:
• First heating cycle: Elements come on [1, 2, 3] and cycle off [3, 2, 1].
• Second heating cycle: Elements come on [2, 3, 1] and cycle off [1, 3, 2].
• Third heating cycle: Elements come on: [3, 1, 2] and cycle off [2, 1, 3].
• Fourth heating cycle: pattern repeats - same as first.
Progressive Sequencing: Only available on models equipped
with multiple heating elements. Elements are energized and de-
energized according to adjustable (1 to 20°F) Differential set points
for each element. Element Rotation - first element on is rotated with
each successive call for heat. First On/First Off - the first heating
element energized at the beginning of a heating cycle is the first
element de-energized at the end of the heating cycle. Successive
heating cycles would progress as follows on a model equipped with
3 heating elements:
• First heating cycle: Elements come on [1, 2, 3] and cycle off [1, 2, 3].
• Second heating cycle: Elements come on [2, 3, 1] and cycle off [2, 3, 1].
• Third heating cycle: Elements come on: [3, 1, 2] and cycle off [3, 1, 2].
• Fourth heating cycle: pattern repeats - same as first.

control systeM operatIon

control systeM features

advanced diagnostics
Plain English text and animated icons display detailed operational and
diagnostic information. LCD screen on the front of the water heater displays
the Sequence of Operation in real time. Fault or Alert messages are displayed
when operational problems occur. Advanced Service menu displays a list of
possible causes for current Fault and Alert conditions to aid in servicing.
economy Mode operation
Control system automatically lowers the Operating Set Point by a
programmed value during user defined time periods. Helps reduce
operating costs during unoccupied or peak demand periods.

control systeM naVIGatIon

The UIM (User Interface Module) is located on the front cabinet of the water
heater. All operational information and user settings are displayed and
accessed using the UIM. The UIM includes five snap acting (momentary)
user input buttons; an Up, Down and 3 Operational Buttons.
up & down Buttons
Used to navigate (up and down) and to select (highlight) menu items.
Also used to adjust or change (increase/decrease, on/off, set time)
various user settings.
operational Buttons
The 3 Operational Buttons are multifunctional. Their current function is
defined by the text that appears directly above each button on the LCD
screen. The function will change depending on what menu is currently
displayed or what menu item is selected. When no text appears on the
LCD screen above an Operational Button there is no function assigned.

the desktop screen

The illustration below shows the control system "Desktop Screen."
This is the default screen. If there are no active Fault or Alert
conditions and no user input for approximately 10 minutes the control
system will return to this screen automatically.
Model Information: Model information and menu titles are shown in
the black bar at the top of the Desktop Screen.
Tank Temperature: Current water temperature as sensed from the
immersion Temperature Probe.
Operating Set Point: Temperature at which the control system will
maintain tank (water) temperature in the Normal Mode. This line of
text will read Economy Set Point whenever the control system is
operating in the Economy Mode.
17
fIGure 4.