9  TROUBLESHOOTING
Phenomenon Cause and action
Stopped operation
All indication lamps on the remote control 
switch are turned OFF.
The micro-computer is activated to protect the device from 
electromagnetic waves. 
The operation can be recovered if it is started from the beginning.
Power failure occurs.
Start the operation from the beginning. 
If the instantaneous power failure is within 2 seconds, the operation 
is restarted automatically.
White steam from indoor unit During the heating operation. It may occur during the defrosting operation in the heating operation.
White smoke from indoor unit The heating operation is begun to use. The dust attached to the heat exchanger is dried.
Mist from indoor unit
The indoor unit is used in a restaurant or a 
kitchen.
Oil is attached to the ns and the heat exchange eciency may be 
decreased.
During the dry operation
It may occur when the air outlet temperature becomes lower. 
Raise the set temperature and the air ow volume.
The cooling operation is performed in high 
humidity environment.
During Frost/Wash Operation This might occur when frost is formed on the heat exchangers ns
Odor from indoor unit The air ow from the indoor unit has odor.
It may occur because the cigarette smoke and room odour are stuck 
inside the indoor unit. 
Ventilate well by the fan mode and clean the air lter, the at panel, 
the air outlet and the air inlet grille. It may be eective for odor 
eliminating.
Sound from indoor unit
Sound is heard when starting or stopping 
the operation.
It is generated because the resin parts are stretched by the 
temperature change and rubbed with other parts.
Sound which water ows or is boiled is 
heard during the operation.
It is generated because the refrigerant ows or the drain-up 
mechanism drains water. Especially, sound may be heard 
when starting the operation or stopping the compressor (for 
approx. 3 minutes).
Growling sound may be heard temporarily 
right after the air ow volume is changed.
It is generated because the fan motor makes temporary sound by 
change of fan speed.
Dew on panel
Dew condensation occurs on the panel or 
the cabinet or dew drops.
It may occur if the operation is performed in high humidity place 
(relative humidity is approx. 80%.) for a long time.
Temperature irregularity
The air ow volume from each air outlet 
and each air outlet temperature are 
irregular.
The temperature irregularity occurs because of the size of air outlet 
and the structure such as the location of heat exchanger.
Turned ON “HOT-START” or "Preheating" on LCD
The indications may be turned ON or ash according to the operation 
mode or condition.
Flashing operation mode on LCD
TROUBLESHOOTING
PMML0551 rev.4 - 07/2023 - A10762310A
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