Water Pump - LG Therma V AHBW A0 Series Service Manual

Checking Key Components of Unit

1.2 Water Pump

Water pump always
running while system
operation
DIP Switch No.5
is set to OFF ?
Water pump
control by
is not correct
* : It is normal condition that water pump runs or stops during system operation (including compressor start-up)
due to specific control logic.
• Water pump does not because of mechanical defects of water pump or wrong wiring at the water pump.
• To correct mechanical defects, contact official After Service Center and replace the water pump.
• To correct wrong wiring, check if wires ʻCN_W/PUMP (A)ʼ connector on the unit PCB and water
A
pump terminal box (black plastic box at the water pump) are connected firmly. Also, check wires are
electrically connected by measuring resistance of each wires (if electrically connected exactly, resis-
tance should be 0 ohm).
• Unit PCB can not make control signal or wrong wiring at the water pump.
• To correct unit PCBʼs making control signal, first check the signal level. Use electric voltage meter
and measure voltage at ʻCN_W/PUMP (A)ʼ connector on the unit PCB. If measured value is not
B 220 V ~ 240 V AC while ʻWater Pump Operating Icon (
PCB is in trouble. In this case, contact official After Service Center and replace the unit PCB.
• To correct wrong wiring, please refer Ⓐ.
Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Start
*Water pump runs
NO
compressor start-up
YES
NO
Heating
Operation
YES
NO
YES
unit PCB
B
NO
and stops while
YES
END
(it is normal
condition)
)ʼ is displayed at control panel, the unit
- 38 -
NO
Water pump always
stop while system
operation
YES
Water pump does
not working
A
LGE Internal Use Only