Hisa Engineering Ltd · A niche brand in the UK. 98 codes across 1 product family, each taken from the manufacturer’s manuals.
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Type the code on your display or a word from its meaning. Each code opens its own page with what it means, whether it is safe and what you can check.
98 codes
| Code | Meaning | Stops? | Homeowner check? |
|---|---|---|---|
| E01 | Wrong-Phase Protection | Not stated | Yes |
| E02 | Power Supply Lack of Phase | Not stated | Yes |
| E03 | Outside Water Flow Switch Fault | Not stated | Yes |
| E04 | Abnormal Communication Between the Main Control Board and Remote Module | Not stated | Yes |
| E05 | High-Pressure Switch One Fault | Not stated | Yes |
| E06 | Low-Pressure Switch One Fault | Not stated | Yes |
| E07 | High-Pressure Switch Two Fault | Not stated | Yes |
| E08 | Low-Pressure Switch Two Fault | Not stated | Yes |
| E09 | Wire controller communication failure | Not stated | Yes |
| E10 | Indoor Side Water Flow Failure | Not stated | Yes |
| E11 | Limited Time Protection | Not stated | Yes |
| E12 | Exhaust Gas Temperature One Too High Fault | Not stated | Yes |
| E13 | Exhaust Gas Temperature Two Too High Fault | Not stated | Yes |
| E14 | Hot Water Tank Temperature Failure | Not stated | Yes |
| E15 | Water Inlet Temperature Sensor Failure | Not stated | Yes |
| E16 | Coil Sensor One Failure | Not stated | Yes |
| E17 | Coil Sensor Two Failure | Not stated | Yes |
| E18 | Exhaust Gas Sensor One Fault | Not stated | Yes |
| E19 | Exhaust Gas Sensor Two Fault | Not stated | Yes |
| E20 | Indoor Temperature Sensor Failure | Not stated | Yes |
| E21 | Environmental Sensor Failure | Not stated | Yes |
| E22 | User Return Water Sensor Failure | Not stated | Yes |
| E23 | Cooling Sub cooling Protection | Not stated | Yes |
| E24 | Board Change Out Temperature Fault | Not stated | Yes |
| E25 | Water Level Switch Malfunction | Not stated | Yes |
| E26 | Anti-Freeze Sensor Malfunction | Not stated | Yes |
| E27 | Water Outlet Sensor Failure | Not stated | Yes |
| E29 | Return Air Sensor One Fault | Not stated | Yes |
| E30 | Return Air Sensor Two Fault | Not stated | Yes |
| E31 | Water Pressure Switch Failure | Not stated | Yes |
| E32 | Excessive Water Temperature Protection | Not stated | Yes |
| E33 | High Pressure One Sensor Fault | Not stated | Yes |
| E34 | Low Pressure One Sensor Fault | Not stated | Yes |
| E37 | The Excessive Temperature Difference Between Inlet And Outlet Water Protection | Not stated | Yes |
| E38 | DC Fan One Failure | Not stated | Yes |
| E39 | DC Fan Two Failure | Not stated | Yes |
| E40 | DC Fan Three Failure | Not stated | Yes |
| E41 | DC Fan Four Failure | Not stated | Yes |
| E42 | Cooling Coil Sensor One Fault | Not stated | Yes |
| E43 | Cooling Coil Sensor Two Fault | Not stated | Yes |
| E44 | Low Ambient Temperature Protection | Not stated | Yes |
| E45 | High Pressure Two Sensor Failure | Not stated | Yes |
| E46 | Low Pressure Two Sensor Failure | Not stated | Yes |
| E47 | Economizer Inlet Sensor One Failure | Not stated | Yes |
| E48 | Economizer Inlet Sensor Two Failure | Not stated | Yes |
| E49 | Economizer Outlet Sensor One Failure | Not stated | Yes |
| E50 | Economizer Outlet Sensor Two Failure | Not stated | Yes |
| E51 | High Pressure One Overvoltage Protection | Not stated | Yes |
| E52 | Low-Pressure One Under Voltage Protection | Not stated | Yes |
| E53 | High-Pressure Two Overvoltage Protection | Not stated | Yes |
| E54 | High Pressure Two Under Voltage Protection | Not stated | Yes |
| E55 | Expansion Board Communication Exception | Not stated | Yes |
| E80 | Power Supply Error | Not stated | Yes |
| E88 | Inverter Module 1 Protection | Not stated | Yes |
| E89 | Inverter Module 2 Protection | Not stated | Yes |
| E94 | Water Pump Feedback Failure | Not stated | Yes |
| E96 | Compressor drive board communication failure | Not stated | Yes |
| E98 | Fan board communication failure | Not stated | Yes |
| EA1 | Cascade model mismatch | Not stated | Yes |
| EA2 | Solar water heater temp. sensor failure | Not stated | Yes |
| EA3 | Zone 2 temp. sensor failure | Not stated | Yes |
| EA4 | Buffer tank temp. sensor failure | Not stated | Yes |
| EA5 | Total water outlet temp. sensor failure | Not stated | Yes |
| P1 | IPM Module Overheat and Shutdown | Not stated | Yes |
| P2 | Compressor Driver Failure | Not stated | Yes |
| P3 | Compressor Overcurrent | Not stated | Yes |
| P4 | Input Voltage Missing Phase | Not stated | Yes |
| P5 | IPM Supply Voltage Failure | Not stated | Yes |
| P6 | Power Component Overheating and Shutdown | Not stated | Yes |
| P7 | Pre-charge Circuit Voltage Failure | Not stated | Yes |
| P8 | DC Bus Overvoltage | Not stated | Yes |
| P9 | DC Bus Undervoltage | Not stated | Yes |
| P10 | AC Input Undervoltage | Not stated | Yes |
| P11 | AC Input Overvoltage | Not stated | Yes |
| P12 | Input Voltage Sampling Failure | Not stated | Yes |
| P13 | DSP and PFC Communication Failure | Not stated | Yes |
| P14 | Board Radiator Temp. Sensor Failure | Not stated | Yes |
| P15 | DSP and Communicate Board Communication Failure | Not stated | Yes |
| P16 | Communication Failure with Motherboard | Not stated | Yes |
| P17 | Compressor Overcurrent Alarm | Not stated | Yes |
| P18 | Compressor Weak Magnetic Protection Alarm | Not stated | Yes |
| P19 | IPM Overheat Alarm | Not stated | Yes |
| P20 | PFC Overheat Alarm | Not stated | Yes |
| P21 | AC Input Overcurrent Alarm | Not stated | Yes |
| P22 | EEPROM Error Alarm | Not stated | Yes |
| P25 | Temperature Sensing Failure Limit | Not stated | Yes |
| P26 | AC Undervoltage Frequency Limit Protection Alarm | Not stated | Yes |
| P33 | IPM Module Overheat and Shutdown | Not stated | Yes |
| P34 | Compressor Missing Phase | Not stated | Yes |
| P35 | Compressor Overload | Not stated | Yes |
| P36 | Input Current Sampling Failure | Not stated | Yes |
| P37 | IPM Supply Voltage Failure | Not stated | Yes |
| P38 | Pre-charge Circuit Voltage Failure | Not stated | Yes |
| P39 | EEPROM Failure | Not stated | Yes |
| P40 | AC Input Overvoltage Failure | Not stated | Yes |
| P41 | Microelectronics Failure | Not stated | Yes |
| P42 | Compressor Type Code Failure | Not stated | Yes |
| P43 | Current Sampling Signal Overcurrent | Not stated | Yes |