Bosch Heat Pump: M15, M18, M20
Re: Fault Codes / Status Codes
| Fault Code Display | |||
| Fault Code | Fault Description | ||
| C3 | The coil sensor (T3) is seated fault in Cooling | ||
| E4 | Temperature Sensor Fault (T3, T4, T3L, T5 or TF) | ||
| E5 | High or Low Voltage Protection | ||
| E6 | Outdoor Fan Motor Fault | ||
| E7 | Compressor Discharge Sensor (T5) is seated fault | ||
| E9 | EEPROM Fault | ||
| H0 | Communication Fault in main control chip | ||
| H5 | 5 times (P2 Fault) in 100 minutes (Hard Lockout) | ||
| H8 | Pressure Transducer Fault (PT) | ||
| P0 | Control Board temperature protection (TF) | ||
| P1 | High Pressure Switch protection (HPS) | ||
| P2 | Low Pressure protection in heating or cooling (PT) | ||
| P3 | Compressor Overcurrent protection | ||
| P4 | High Compressor Discharge temperature protection (T5) | ||
| P5 | Condenser Coil temperature protection in Cooling (T3) | ||
| P8 | Outdoor Fan Motor hurricane/typhoon protection | ||
| PH | Low discharge superheat protection | ||
| F1 | High Pressure Switch (HPS) fault | ||
| L0-L9 | IPM Fault | ||
| AtL | Ambient Temperature limited | ||
| System Protection Status Codes | |||
| Display | Description | ||
| L | Outdoor Coil (T3) limited condition | ||
| D | Compressor Discharge (T5) limited condition | ||
| P | Compressor ratio limited condition | ||
| F | T5 limited condition | ||
| C | Current limited condition | ||
| U | Under low voltage limited condition | ||
| A | Oil return mode | ||
| dF | Defrost mode | ||