McQuay Air Conditioner Error Codes Error Codes Problem E1 Compressor 2 low pressure faulty E2 Compressor 2 high pressure faulty E3 Compressor 2 overload E4 Indoor coil 2 temperature sensor fault E5 System 2 leaving water temperature 2 faulty F2 Indoor coil 1 temperature sensor fault F4 Return air temperature sensor fault F6 Communication faulty F9 Compressor 1 refrigerant leak FE Compressor 2 refrigerant leak H1 Compressor 1 overload H4 Compressor 1 high pressure faulty L1 Compressor 1 low pressure faulty L3 Temperature of water entering too high or low L4 Water flow switch faulty L5 System 1 leaving water temperature 1 faulty McQuay Air Conditioner Remote Control Single Split Inverter-Y Model Indoor Series Error Codes Error Description 0 Normal F6 Heat exchanger overheat U0 Insufficient gas H0 Compressor sensor system abnormality U2 DC voltage out of range H3 High pressure switch error U4 Communication error H6 Position sensor abnormality U7 Signal transmission error (on o...