General Problem Symptoms and Check Items SiUS041501E55 Service Diagnosis1. General Problem Symptoms and Check ItemsSymptom Check Item Details 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 with theoutdoor unit. —Check the outdoor temperature. Heating operation cannot be used when theoutdoor temperature is 18°CWB (64.4°FWB) orhigher, and cooling operation cannot be used whenthe outdoor temperature is below 10°CDB(50°FDB).—Diagnose with remote controllerindication. — 60Check the remote controlleraddresses.Check if address settings for the remote controllerand indoor unit are correct. 106Operation 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 (64.4°FWB) orhigher, and cooling operation cannot be used whenthe outdoor temperature is below 10°CDB(50°FDB).—Diagnose with remote controllerindication. — 60The 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 the electronicexpansion valve works. —Diagnose with remote controllerindication. — 60Diagnose by service port pressureand operating current. Check for refrigerant shortage. —Large operating noise andvibrations Check the output voltage of thepower module. — 100Check the power module. — —Check the installation condition. Check if the required spaces for installation(specified in the installation manual) are provided. —
