AC Fan Coil Unit Two-pipe Wall-
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12.8 Troubles and causes of air conditioner 
If one of the following malfunctions occur, stop operation, shut off the power, and contact with your dealer. 
•  The operation lamp is flashing rapidly (twice every second) 
•  This lamp is still flashing rapidly after turn off the power and turn on again. 
•  Remote controller receives malfunction or the button does not work well. 
•  A safety device such as a fuse, a breaker frequently actuates. 
•  Water leaks from indoor unit. 
•  Other malfunctions. 
Symptoms  Causes  Solution 
Unit does not start 
•  Power failure; 
•  Power switch is off; 
•  Fuse of power switch may have burned; 
•  Batteries of remote controller exhausted or other 
problem of controller. 
•  Wait for the comeback of power; 
•  Switch on the power; 
•  Replace the fuse; 
•  Replace the batteries or check the controller. 
Air flowing normally but 
completely can’t cooling 
•  Temperature is not set correctly.  •  Set the temperature properly. 
Low cooling effect 
•  Indoor unit heat exchanger is dirty; 
•  The air filter is dirty; 
•  Inlet of indoor unit is blocked; 
•  Doors and windows are open; 
•  Sunlight shine directly; 
•  Too many heat resources; 
•  Outdoor temperature is too high. 
•  Clean the heat exchanger; 
•  Clean the air filter; 
•  Eliminate all dirties and make air smooth; 
•  Close doors and windows; 
•  Make curtains in order to shelter from sunshine; 
•  Reduce heat resource; 
•  AC cooling capacity reduces (normal). 
Low heating effect 
•  Outdoor temperature is lower than 7℃; 
•  Doors and windows are not completely closed. 
•  Use heating device; 
•  Close doors and windows. 
 
12.9 Troubles and causes of remote controller 
Before asking for serving or repairing, check the following points. 
Symptoms  Causes  Solution 
The fan speed cannot be changed. 
•  Check whether the MODE indicated on the 
display is “AUTO”. 
When the automatic mode is selected, the air 
conditioner will automatically change the fan 
speed. 
•  Protection against hot wind in cooling mode. 
•  Protection against cold wind in heating mode. 
Reduce the temperature of inlet in cooling 
mode rise the temperature of inlet in heating 
mode. 
The remote controller signal is not 
transmitted even when the ON/OFF 
button is pushed. 
•  Check whether the batteries in the remote 
controller are exhausted. 
The power supply is off. 
The TEMP. indicator does not come on. 
•  Check whether the MODE indicated on the 
display is “FAN ONLY”. 
The temperature cannot be set during FAN 
mode. 
The indication on the display disappears 
after a lapse of time. 
•  Check whether the timer operation has come to 
an end when the “TIMER OFF” is indicated on 
the display. 
The air conditioner operation will stop up to the 
set time. 
The TIMER ON indicator goes off after a 
lapse of certain time. 
•  Check whether the timer operation is started 
when the “TIME ON” is indicated on the display. 
Up to the set time, the air conditioner will 
automatically start and the appropriate indicator 
will go off. 
No receiving tone sounds from the indoor 
unit even when the ON/OFF button is 
pressed. 
•  Check whether the signal transmitter of the 
remote controller is properly directed to the 
infrared signal receiver of the indoor unit when 
the ON/OFF button is pressed. 
Directly transmit the signal transmitter of the 
remote controller to the infrared signal receiver 
of the indoor unit, and then repeat pushing the 
ON/OFF button twice.