After the unit fills, the control panel LEDS are flashing On, Off, On, Off, any suggestions ?

The error code you are getting means:
“Low-level water error. When Low Level is detected to cause Error even after the water supply resumes after Low Level is detected for the 1st time Low Level Sensor terminal not connected, Possible defect : Low Level Sensor , Main PBA.”

Enter into service test mode

Press the ‗Heavy‘ + ‗Delicate‘ + ‗Power‘ buttons at the same time for two seconds to enter Service Inspection Mode.
All LEDs are displayed for the first two seconds and then Software-Ver. It will be indicated Binary Code using ‗Wash +
Dry + Clean + Child Lock‘ LED.
You can change the mode by pressing the Normal button once more. If press the Normal button in any mode, mode will
be changed to next mode.
If ‗Heavy + Quick‘ LED, ‗Heavy‘ LED or ‗Heavy + Delicate + Quick‘ LED error occur, enter the Service Inspection Mode
after resolving problem.
Service Inspection Mode is described in the following table. When you activate this inspection mode, the door must be closed.
No.1 ‘Quick’ LED Inlet Valve
Flow Meter
Low Level
Sensor
Water Supply
Error
Low Level Water
Error
‘Normal’ +
‘Heavy’ +
‘Delicate’ LED
If Door is open, ‘Delicate’ + ‘Quick’ LED will blink.
Water is supplying af ter low level S/W is detected. If low level S/W is high, Draining at f irst.
If water is not supplied, Water Supply Error (‘Quick’ LED) will blink.
When water level is low af ter water is supplied, Low Level Water Error (‘Normal’ + ‘Heavy’
+ ‘Quick’ LED) will blink.
When Turbidity problem is detected af ter water is supplied, ‘Normal’ + ‘Heavy’ + ‘Delicate’
LED will blink.
If all functions in this mode are completed, ‘Wash’ LED will blink.
No.2 ‘Delicate’
LED
Circulation
Motor
A nozzle does
not inject water.
If Low Level S/W is detected before Circulation Motor is operating, ‘Sanitize’ LED will blink.
No.3 ‘Delicate’ +
‘Quick’ LED
Circulation
Motor
Heater
Thermistor
Heater Error If Low Level S/W is detected before Circulation Motor is operating, ‘Sanitize’ LED will blink.
Circulation Motor and Heater will be operated.
When the temperature is 60℃ or above, the heater is turned of f and ‘Wash’ LED will blink.
If Heater or Thermistor have problems, the Heater Error (‗Heavy‘ + Delicate‘ LED) will blink.
Dispenser will operate during 2 minutes and 10 seconds only one time.
No.4 ‘Heavy’ +
‘Quick’ LED
Fan Motor
Dispensor
The Fan Motor
does not work.
Operate Vent Motor and check whether Rinse aid is f illed.
If there is not rinse in Dispenser, Rinse Ref illed light is ON.
No.5 ‘Heavy’ +
‘Delicate’
LED
Overf low
Sensor
Over level water
error
Water is supplied until Over Level Water Error (‘Heavy’ + ‘Quick’ LED) is blinked.
If Over Level Water Error occurs, overf low sensor is OK.
No.6 ‘Heavy’ +
‘Delicate’ +
‘Quick’ LED
Drain Pump
Low Level
Sensor
Drain Error Drain pump will work until low level is detected.
If Low level is not detected af ter 60 seconds, Drain Error (‘Delicate’ LED) will blink.
No.7 ‘Normal’ +
‘Quick’ LED
Inlet Valve
Circulation
Motor
Fan Motor
Drain Pump
Heater
Operate each operating part when the button is pressed. (See the below)
When the ‘Quick’ button is pressed, it toggles between Inlet Valve On (‘Quick’ LED On) ->
Of f (‘Quick’ LED Of f ).
When ‗Heavy’ button is pressed, it works Circulation Motor On (‘Heavy’ LED On) -> Of f
(‘Heavy’ LED Of f ) -> Fan Motor On (‘Heavy’ LED On) -> Of f (‘Heavy’ LED Of f ), Drain
Pump On (‘Heavy’ LED On) -> Of f (‘Heavy’ LED Of f )
When ‘Delicate’ button is pressed, it woks Heater On (‘Delicate’ LED On during 2 seconds).
When a dif ferent button is pressed during individual operation of the operating part,
operating part is stopped and the applicable operation f or the pressed button‘s f unction will
start.