SiUS331604E Troubleshooting by Error CodeService Diagnosis 2224.57 CheckCheck for causes of rise in high pressureReferring to the Fault Tree Analysis (FTA) shown below, probe the defective points.Note: ∗1: In cooling, it is normal if the outdoor unit electronic expansion valve is fully open.∗2: In heating, the indoor unit electronic expansion valve is used for subcooling degree control.CHECK 1Short circuitRise in highpressureLocalpressureriseHigh piperesistanceStop valve closedBent or crashed pipeClogging of foreignmaterials[In cooling]If the outdoor unit electronicexpansion valve is throttled:(∗1.)Defective outdoorunit electronicexpansion valveDefective indoorunit electronicexpansion valveDefective valve coilDefective valve bodyA temperature difference in excess of 10°C (50˚F)between the inlet and the outlet is deemed to be abnormal.DefectivecontrolDefective high pressure sensorDefective mainPCBDefectivehigh pressurecontrol Defective valve coilDefective valve body[In heating]If the indoor unit electronicexpansion valve excessivelythrottled:(∗2.)DefectivecontrolDefective high pressure sensorDefective indoor unitliquid pipe thermistorDefective mainPCB[In cooling]High suctionairtemperatureof thecondenser[In heating]High suction airtemperature ofoutdoor unitShort circuitHigh outdoor airtemperatureHigh suctionair temperatureof indoor unit High roomtemperatureDefective suction air thermistor of indoor unitHigh suction air temperature of outdoor unitDefective outdoor air temperature thermistor of outdoor unitDegradationin condensingcapacityDirty condenserMixing of non-condensable gasDecreasedairflow rateDecreasedfanoutputDefective fanmotorDefective mainPCB (Includingcapacity setting)HighairflowpassageresistanceDirty filterObstacleExcessive refrigerant chargingImproper model selection [In heating]←Check to be sure the stop valve is open.←Conduct visual checks for pipe conditions.←Is there any temperature difference caused beforeand after the filter or branch pipe.←Are the coil resistance and insulation normal?←Is the pressure value checked with the Service Checkercorresponding to the measurement value of the pressure sensor?←Are the voltage characteristics normal?←Are the coil resistance and insulationnormal?←Is the pressure value checked with the ServiceChecker corresponding to the measurement value ofthe pressure sensor?←In the connector properly connected?Are the thermistor resistance characteristics normal?←Are the voltage characteristics normal?←Is the room temperature more than 27°C (80.6˚F)?←Is the connector properly connected?Are the thermistor resistance characteristics normal?←Is the outdoor air temperature more than 16°CWB(60.8˚FWB)?←Is the connector properly connected?Are the thermistor resistance characteristics normal?←Is the heat exchanger clogged? (In cooling)←Is air or else mixed in the refrigerant system?←Can the fan motor be rotated with hands?Are the motor coil resistance andinsulation normal?←If a spare PCB is installed, is the capacitysetting properly made?←Is the air filter clogged?←Is there any obstacle in the airflow passage?←Refer to CHECK 6 .←Is the indoor unit too small compared tothe large-sized outdoor unit?←Is the suction air temperature more than 43°C(109°F)?←Is the outdoor air temperature more than 43°C(109°F)?←Is the suction air temperature more than 27°C(80.6˚F)?
