Noise from 
indoor unit
Collision sound 
of the machine
Flowing sound 
of the liquid
Sound of the 
running fan motor
Sound of plastic 
pieces rubbing or 
deforming
Oscillation 
sound
Sound of running 
fan motor 
 Vane imbalance or distortion.
Sound made by 
cooling operation
Refrigerant circulation or vane distortion.
Sound of running 
compressor
Something wrong with the compressor, such as 
oil shortage, valve slice distortion.  
         Noisy
Fixing bolts somewhere may loose or rub, some 
spare parts may not match very well.
 
Refrigerant  circulation or pressure change of 
refrigerant while switch on/off.
 Vane imbalance or distortion, rupture;  loose 
screw of vane. 
Plastic pieces deform due to expansion when 
hot and shrink when cold. Or some spare parts 
may not match very well.
Noise from 
Outdoor unit
Collision sound 
of the machine
  Collision of the pipeline, fixing screws loose or 
deform caused by rubbing.
Inappropriate installation method; the unit 
does not match with the installation kit very well 
or the compressor quivers acutely. 
The whole unit resonates thedoor and window.
Sound made by 
compressor or motor 
The compressor or motor makes abnormal noise.
Condensed water is attached to the vane. 
Vane imbalance or distortion.
          Resonance sound
          Collision sound of the 
machine
          Flowing sound of 
condensed water
          Sound of running fan 
motor 
Noise from 
the whole 
unit
The unit does not match with the installation kit 
very well 
         Collision of the pipeline, fixing screws loose or 
plastic pieces deform.
FAULT DIAGNOSIS BY SYMPTOM
15