A.O. Smith 100 Power Vent DV Series 120, 317443-000 Operating States, Control System Menus

Operating States

The current operational state of the water heater is displayed on the Desktop screen as the "Status." The common operational states are described in the table below.

Table 4.

State	Description
Standby	The water heater is not in an active heating cycle. IE: the Tank Temperature is at or above the Operating Set Point.
Input Verification	The control system is conducting a diagnostic check at the beginning of a heating cycle.
Short Cycle Delay	The control system is waiting for a pre-defined time period to expire before initiating a heating cycle. This prevents "short-
	cycling" which can greatly accelerate wear on components such as the Igniter and Combustion Blower.
	Note: If the control system is in this operational state increase the Differential setting in the Temperatures menu to lengthen
	heating cycles.
Pre-Purge	The Combustion Blower is energized to flush residual flue gases from the combustion chamber prior to ignition.
Igniter Warm Up	The Igniter is energized and is currently warming up to ensure proper ignition.
Ignition Activation	The 24 Volt Gas Valve is energized and opens to allow fuel gas to flow to the Main Burner.
Ignition Verification	The control system is monitoring the Flame Sensor for the required minimum flame sensing current.
Inter-Purge	The Combustion Blower is energized to flush residual fuel gas from the combustion chamber after a failed ignition attempt.
Heating	Ignition was successful, flame sensing current has been established. The water in the storage tank is being heated.
Post-Purge	The Combustion Blower is energized to flush residual flue gases from the combustion chamber at the end of a heating
	cycle.
Fault	The control system has detected a Fault condition. Heating operation is disabled (control system lock out) until the Fault
	condition is corrected. Power to the water heater must be cycled off and on to reset the control system.
	Note: Cycling power will not reset the control system if the condition that caused the Fault has not been corrected.

Control System Menus

From the Desktop screen pressing the Operational button directly below "Menu" on the LCD will display the "Main Menu" this is where all control system menus are located. The table below describes the control system menus.

Table 5.

Menu	Description
Temperatures	Most commonly accessed menu. Contains the Operating Set Point and Differential user settings.
Heater Status	This menus displays the current state of all pressure switches and the ECO (open/closed). The on/off status of the
	Combustion Blower, 24 Volt Gas Valve, Igniter, Flame Sensor and other monitored water heater components are
	displayed in this menu.
Display Settings	Temperature units (°F or °C), the LCD appearance (brightness/contrast) and backlight delay user adjustable settings
	are located in this menu.
Heater Information	Elapsed time of operation, total heating cycle time, heating cycle count, heating on time along with UIM and CCB
	software revisions can be viewed in this menu.
Current Fault	Displays any current Alert or Fault messages.
Fault History	This control system menu retains a list of the last nine (9) Fault and Alert messages with a time stamp. The newest
	event will replace the oldest. Fault history memory is cleared after 30 days.
Fault Occurrence	This control system menu retains a running total of how many times each Fault condition has occurred since the water
	heater was first installed. Fault occurrences numbers are saved in the CCB memory indefinitely.
	Note: if the CCB is replaced during service the fault occurrence historical information for the water heater is lost.
Restore Factory Defaults	This control system feature allows the user to restore control system user settings to their factory default settings.
	Display Settings preferences ARE NOT changed when factory defaults are restored.
Help Screens	Text based operational and user information explaining how to change user settings, navigate the control system menus
	and icon descriptions.

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