Service Diagnosis
45
Domestic Air Conditioner
7.Service Diagnosis 
7.1 Caution for Diagnosis 
The operation lamp flashes when any of the following errors is detected. 
1.When a protection device of the indoor or outdoor unit is activated or when the thermistor malfunctions, 
disabling equipment operation. 
2.When a signal transmission error occurs between the indoor and outdoor units.In either case, conduct the 
diagnostic procedure described in the following pages.
7.2.Problem Symptoms and Measures 
Symptom  Check Item  Details of Measure 
Check the power supply.  Check to make sure that the rated voltage is supplied. None of the units 
operates 
Check the indoor PCB  Check to make sure that the indoor PCB is broken 
Operation 
sometimes stops. 
Check the power supply.  A power failure of 2 to 10 cycles can stop air conditioner 
operation.  
Check for faulty operation 
of the electronic 
expansion valve. 
Set the units to cooling operation, and compare the 
temperatures of the liquid side connection pipes of the 
connection section among rooms to check the opening and 
closing operation of the electronic expansion valves of the 
individual units. 
 
 
 
Equipment 
operates but does 
not cool, or does 
not heat (only for 
heat pump) 
Diagnosis by service port 
pressure and operating 
current. 
Check for insufficient gas. 
 
Large operating 
noise and 
vibrations 
 
 
Check the installation 
condition. 
 
Check to make sure that the required spaces for 
installation (specified in the Technical Guide, etc.) are 
provided.  
 
 
7.4.Error Codes and Description indoor display 
Code indication 
 
Indoor 
displaying 
panel code 
indication 
Outdoor 
(LED1 flash 
times) 
fault description 
Reference
Page 
Indoor and 
Outdoor 
E7 15 
Communication fault between indoor and 
outdoor units 
Page .62 
E1  --  Room temperature sensor failure    Page .50 
E2  --  Heat-exchange sensor failure    Page .50 
 15. egaP rorre MORPEE roodnI -- 4E
 
Indoor Malfunction 
E14  --  Indoor fan motor malfunction  Page .52 
 15. egaP rorre MORPEE  roodtuO 1 21F 
 
F1 
2 
 45. egaP MPI fo noitcetorp ehT