General Problem Symptoms and Check Items SiBE041029EC51 Service Diagnosis1. General Problem Symptoms and Check ItemsSymptom Check Item Measures ReferencePageThe unit does not operate. Check the power supply. Check if the rated voltage is supplied. —Check the type of the indoor unit. Check if the indoor unit type is compatible withthe outdoor unit. —Check the outdoor temperature. Heating operation cannot be used when theoutdoor temperature is 18°CWB or higher, andcooling operation cannot be used when theoutdoor temperature is below –10°CDB.—Diagnose with remote controllerindication. — 56Check the remote controlleraddresses. Check if address settings for the remotecontroller and indoor unit are correct. 108Operation sometimesstops.Check the power supply. A power failure of 2 to 10 cycles stops airconditioner operation. (Operation lamp OFF) —Check the outdoor temperature. Heating operation cannot be used when theoutdoor temperature is 18°CWB or higher, andcooling operation cannot be used when theoutdoor temperature is below –10°CDB.—Diagnose with remote controllerindication. — 56The unit operates but doesnot cool, or does not heat. Check for wiring and piping errors inthe connection between the indoorunit and outdoor unit. — —Check for thermistor detection errors. Check if the thermistor is mounted securely. —Check for faulty operation of theelectronic expansion valve. Set the unit to cooling operation, and check thetemperature of the liquid pipe to see if theelectronic expansion valve works. —Diagnose with remote controllerindication. — 56Diagnose by service port pressureand operating current.Check for refrigerant shortage. 62Large operating noise andvibrations Check the output voltage of thepower module. — 102Check the power module. — —Check the installation condition. Check if the required spaces for installation(specified in the installation manual) areprovided. —
