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17 Troubleshooting Guide
17.1. Self Diagnosis Function (CU-2E15LBE and CU-2E18LBE)
Abnormality
judgement
Emergency
operation
Primary location to verify
Diagnosis
display
Abnormality or protection control
H11 Indoor/outdoor abnormal
communication
> 1 min after starting
operation
Indoor fan operation can
start by entering into force
cooling operation
• Internal/external cable
connections
• Indoor/outdoor PCB
H12 Indoor unit capacity unmatched — — • Indoor unit total capacity
H14 Intake air temperature unmatched — — • Intake air temperature sensor
(defective or disconnected)
H16 Outdoor current transformer — — • Decreased amount of refrigerant
• Outdoor PCB
H19 Indoor fan motor mechanism lock — — • Fan motor
• Indoor PCB
H23 Indoor heat exchanger temperature
sensor
Continue for 5 sec — • Heat exchanger temperature
sensor
(defective or disconnected)
H27 Outdoor air temperature sensor Continue for 5 sec — • Outdoor air temperature sensor
(defective or disconnected)
H28 Outdoor heat exchanger temperature
sensor 1
Continue for 5 sec — • Outdoor heat exchanger
temperature sensor
(defective or disconnected)
H30 Outdoor discharge pipe temperature
sensor
Continue for 5 sec — • Outdoor discharge pipe
temperature sensor
(defective or disconnected)
H32 Outdoor heat exchanger temperature
sensor 2 (discharge pipe temp)
Continue for 5 sec — • Outdoor heat exchanger
temperature sensor
(defective or disconnected)
H34 Outdoor heatsink temperature sensor at
Control Board
Continue for 2 sec — • Outdoor heatsink temperature
sensor at control board
(defective or disconnected)
H36 Outdoor gas pipe temperature sensor Continue for 2 sec — • Outdoor gas pipe temperature
sensor
(defective or disconnected)
H37 Outdoor liquid pipe temperature sensor Continue for 2 sec — • Outdoor liquid pipe temperature
sensor
(defective or disconnected)
H39 Abnormal indoor operating unit or
standby units
— — • Piping connection error
• Indoor/outdoor connection cable
connection error
H41 Abnormal wiring or piping connection — — • Wiring or piping connection
H97 Outdoor fan motor mechanism lock — — • Outdoor fan motor
H98 Indoor high pressure protection — — • Air filter dirty
• Air circulation short circuit
H99 Indoor heat exchanger freeze
protection
— — • Insufficient refrigerant
• Air filter dirty
F11 Cooling/heating cycle changeover
abnormality
4 times occurrences
within 30 minutes
— • 4-way valve
•V-coil
F17 Indoor standby unit freezing — — • Outdoor expansion valve leakage
• Indoor unit pipe temperature
sensor
F90 PFC circuit protection — — • Outdoor PCB
• Outdoor fan motor
F91 Refrigeration cycle abnormality 2 times occurrences
within 20 minutes
— • No refrigerant (3-way valve is
closed)