Blue Series Troubleshooting (18K & 24K)

NO.	Malfunction Name	Display Method of Indoor Unit				Display Method of Outdoor Unit				A/C Status	Possible Causes
		Dual-8 Code Display	Indicator Display			Indicator Display
			Operation Indicator	Cooling Indicator	Heating Indicator	D40/D5	D41/D6	D42/D16	D43/D30
1	System High Pressure Protection	E1	Off 3s blink once			off	Blinking	Blinking	Blinking	During cooling and drying operation, all loads except the indoor fan stop operation. During heating operation, the entire unit stops.	Refrigerant was superabundant; Poor heat exchange (including filth blockage of heat exchanger and bad radiating environment); Ambient temperature is too high.
2	Antifreezing protection	E2	Off 3s and blink twice			On	Off	On	Off	During cooling and drying operation, compressor and outdoor fan stop while indoor fan operates.	Poor air-return in indoor unit; Fan speed is abnormal; Evaporator is dirty;
3	High discharge temperature protection of compressor	E4	Off 3s and blink 4 times			On	Off	On	Blinking	During cooling and drying operation, compressor and outdoor fan stop while indoor fan operates. During heating, all loads stop.	Please refer to the service manual
4	Overcurrent protection	E5	Off 3s and blink 5 times			Off	On	Blinking	Off	During cooling and drying operation, compressor and outdoor fan stop while indoor fan operates. During heating, all loads stop.	Supply voltage is unstable; Supply voltage is too low and load is too high; Evaporator is dirty;
5	Communication malfunction	E6	Off 3s and blink 6 times			Off	Off	Off	Blinking	During cooling and drying operation, compressor and outdoor fan stop while indoor fan operates. During heating, all loads stop.	Please refer to the service manual
7	High temperature resistant protection	E8	Off 3s and blink 8 times			On	Off	On	On	During cooling and drying operation, compressor and outdoor fan stop while indoor fan operates. During heating, all loads stop.	Please refer to the service manual