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COMPREHENSIVE APPLICATION AND INSTALLATION MANUAL
LG Electronics
Installation check listConguration
System Design ApplicationsIntroduction
Code  
No.
Description Cause Normal Condition
14 Problem in ow switch
• Flow switch is open 
while internal water 
pump is working 
• Flow switch is open 
while DIP switch 
No.5 of Main PCB 
assembly(Heater) is set 
as on.
• Flow switch should be 
closed while internal water 
pump is working or DIP 
switch No. 5 of Main PCB 
assembly(Heater) is set 
as on
• Flow switch should be open 
while internal water pump is 
not working
15 Water pipe overheated
• Abnormal operation of 
electric heater
• Leaving water tempera
-
ture is above 57 °C
• If there is no problem in 
electric heater control, 
possible maximum leaving 
water temperature is 57 °C
20 Thermal fuse is damaged
• Thermal fuse is cut off 
by abnormal overheat
-
ing of internal electric 
heater
• Mechanical fault at 
thermal fuse
• Wire is damaged
• This error will not be hap
-
pened if temperature of 
electric heater tank is below 
80 °C
2.2 Trouble shooting
 
No Problem Reason Solution
1
Heating or Cooling 
is not satisfactory.
Setting target 
temperature is not 
proper.
• Set target temperature correctly.
• Check if temperature is water-based or air-
based. See ‘Remote sensor active’ and ‘Temp. 
selection’ chapter.
Charged water is 
not enough.
• Check  pressure gage and charge more water 
until pressure gage is indicating 200~250 kPa.
Water ow rate 
is row.
• Check if strainer gathers too much particles. 
 
If so, strainer should be cleaned.
• Check if pressure gage indicates above 4 Bar.
• Check if water pipe is getting closed due to 
stacked particles or lime.
2
Although electric 
power supply is 
OK(remote control
-
ler displays informa-
tion), the unit does 
not start working.
Water inlet 
temperature is too 
high.
• If water inlet temperature is above 55 °C, unit 
does not operate in order to protect the system.
Water inlet tem
-
perature is too low.
• If water inlet temperature is below 5 °C, the 
unit does not operate in order to protect the 
system. Wait while unit warms up the water inlet 
temperature.
 3 Water pump noise.
Air purging is 
not completely 
nished.
• Open the cap of air purge and charge more 
water until pressure gage is indicating 200~250 
kPa.
• If water does not splash out when the tip (at the 
top of the hole) is pressed, then air purging is 
not completed yet. If well purged, the water will 
splash out like fountain.
Water pressure 
is low.
• Check if pressure gage indicates above 30 kPa.
• Check if the expansion tank and pressure gage 
operate well.
4
Water is ood out 
through drain hose.
Too much water is 
charged.
• Flood out the water by opening the switch of 
the safety valve until pressure gage is indicating 
200~250 kPa.
Expansion tank is 
damaged.
• Replace the expansion tank.
5 DHW is not hot.
Thermal protector 
of water tank 
heater is activated.
• Open the side panel of the DHW tank and push 
the reset button of the thermal protector. (for 
more detail information, please refer to installa
-
tion manual of DHW tank.)
DHW heating is 
disabled.
• Select DHW heating operation and identify if 
icon is displayed on the remote controller.