General Problem Symptoms and Check Items SiUS091601E61 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 is not available when the outdoortemperature is -25°CWB (-13°FWB) or higher, andcooling operation is not available when the outdoortemperature is below 10°CDB (50°FDB).—Diagnose with remote controllerindication. — 69Check the remote controlleraddresses. Check if address settings for the remote controllerand indoor unit are correct. 119Operation 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 is not available when the outdoortemperature is -25°CWB (-13°FWB) or higher, andcooling operation is not available when the outdoortemperature is below 10°CDB (50°FDB).—Diagnose with remote controllerindication. — 69The 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. — 69Diagnose by service port pressureand operating current.Check for refrigerant shortage. —Large operating noise andvibrationsCheck the output voltage of thepower module. — 111Check the power module. — —Check the installation condition. Check if the required spaces for installation(specified in the installation manual) are provided. —
