SiUS041829E General Problem Symptoms and Check ItemsPart 6 Service Diagnosis 651. General Problem Symptoms and Check ItemsSymptom Check Item Measures ReferencePageThe unit does notoperate.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/cooling operations are not available whenthe outdoor temperature is out of the operationlimit. Check the reference page for the operationlimit.139Diagnose with remote controllerindication. — 70Check the remote controlleraddresses.Check if address settings for the remote controllerand indoor unit are correct. 129Operation sometimesstops.Check the power supply. A power failure of 2 to 10 cycles stops airconditioner operation. (Operation lamp OFF) —Check the outdoor temperature. Heating/cooling operations are not available whenthe outdoor temperature is out of the operationlimit. Check the reference page for the operationlimit.139Diagnose with remote controllerindication. — 70The unit operates butdoes not cool, or doesnot 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. — 70Diagnose by service port pressureand operating current. Check for refrigerant shortage. —Large operating noiseand vibrationsCheck the output voltage of the powermodule. — 122Check the power module. — —Check the installation condition. Check if the required spaces for installation(specified in the installation manual) are provided. —
