18819.4 Error Codes TableDiagnosis display Abnormality/Protection control Abnormality judgement Primary location to verifyH00 No abnormality detected — —H12 Indoor/Outdoor capacity unmatched 90s after power supply Indoor/outdoor connection wire Indoor/outdoor PCB Specification and combination table incatalogueH15 Outdoor compressor temperature sensorabnormality Continue for 5 sec. Compressor temperature sensor(defective or disconnected)H20 Water pump abnormality Continue for 10 sec. Indoor PCB Water pump (malfunction)H23 Indoor refrigerant liquid temperaturesensor abnormality Continue for 5 sec. Refrigerant liquid temperature sensor(defective or disconnected)H27 Service valve error Continue for 5 minutes High pressure sensor (defective ordisconnected)H28 Abnormal solar sensor Continue for 5 sec. Solar temperature sensor (defective ordisconnected)H31 Abnormal swimming pool sensor Continue for 5 sec. Pool temperature sensor (defective ordisconnected)H36 Abnormal buffer tank sensor Continue for 5 sec. Buffer tank sensor (defective ordisconnected)H38 Brand code not match When indoor and outdoorbrand code not same —H42 Compressor low pressure abnormality — Outdoor pipe temperature sensor Clogged expansion valve or strainer Insufficient refrigerant Outdoor PCB CompressorH43 Abnormal Zone 1 sensor Continue for 5 sec. Water temperature Zone 1 sensorH44 Abnormal Zone 2 sensor Continue for 5 sec. Water temperature Zone 2 sensorH62 Water flow switch abnormality Continue for 1 min. Water flow switch*H63 Refrigerant low pressure abnormality Continue for 5 sec. Outdoor low pressure sensor(defective or disconnected)H64 Refrigerant high pressure abnormality Continue for 5 sec. Outdoor high pressure sensor(defective or disconnected)*H65 Deice circulation error Continue for 10 sec. Water flow switch sensor (defective ordisconnected) Water pump malfunction Buffer tank (is used)H67 Abnormal External Thermistor 1 Continue for 5 sec. Room temperature Zone 1 sensorH68 Abnormal External Thermistor 2 Continue for 5 sec. Room temperature Zone 2 sensorH70 Back-up heater OLP abnormality Continue for 60 sec. Back-up heater OLP(Disconnection or activated)H72 Tank sensor abnormal Continue for 5 sec. Tank sensorH74 PCB communication error Communication or transfererror Indoor main PCB and Sub PCBH75 Low water temperature controlRoom heater disable and deicerequest to operate under lowwater temperature Heater operation must enable toincrease water temperatureH76 Indoor - control panel communicationabnormality — Indoor - control panel(defective or disconnected)H90 Indoor/outdoor abnormal communication > 1 min after starting operation Internal/external cable connections Indoor/Outdoor PCBH91 Tank heater OLP abnormality Continue for 60 sec. Tank heater OLP(Disconnection or activated)H95 Indoor/Outdoor wrong connection — Indoor/Outdoor supply voltageH98 Outdoor high pressure overloadprotection — Outdoor high pressure sensor Water pump or water leakage Clogged expansion valve or strainer Excess refrigerant Outdoor PCBH99 Indoor heat exchanger freeze prevention — Indoor heat exchanger Refrigerant shortageF12 Pressure switch activate 4 times occurrence within20 minutes Pressure switchF14 Outdoor compressor abnormal revolution 4 times occurrence within20 minutes Outdoor compressorF15 Outdoor fan motor lock abnormality 2 times occurrence within30 minutes Outdoor PCB Outdoor fan motorF16 Total running current protection 3 times occurrence within20 minutes Excess refrigerant Outdoor PCB