TOYOTOMI
U-Match 5 SERIES UNIT SERVICE MANUAL
■Ambient temperature of IDU and ODU is too low
Troubleshooting:
3.4.3 ―E3‖ Compressor Low-pressure Protection, Refrigerant Shortage
Protection, Refrigerant Recovery Mode
Error display: ODU mainboard, IDU wired control and IDU receiver light board will display
E3
Error judgment condition and method:
It is judged through the action of low pressure switch. If the low pressure switch is cut off, it is judged that low pressure is too low
and the system stops operation for protection.
Possible reason:
■Cut-off valve of ODU is not fully opened;
■Low pressure sensor is abnormal;
■Outdoor or indoor fan is not working properly;
■IDU filter or air duct is blocked (cooling mode);
■Ambient temperature is too low;
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