Midea R32 M thermal Arctic Mono fault E1

What it means

Phase sequence error on 3-phase power supply. Only applies to 3-phase models. M thermal Mono stops running. Error code displayed on refrigerant system main control board and user interface.

Likely causes

1. Power supply phases not connected in correct sequence, power supply terminals loose, power supply abnormal, main PCB damaged
2. Incorrect phase sequence on 3-phase power supply
3. Power supply terminals loose
4. Power supply abnormal
5. Main PCB damaged
6. Main board fuse damaged/blown
7. Hydronic box main PCB fault
8. Damaged cables between hydronic box main PCB and outdoor unit main PCB
9. Outdoor unit main PCB fault
10. Incorrect or abnormal input power supply (N or L)
11. Insufficient refrigerant caused by refrigerant leakage
12. Low pressure side blocked by crushed or bent pipe, blocked EXV, or dirty filter
13. Poor air side heat exchanger heat exchange in heating or DHW mode
14. Insufficient water flow rate in cooling mode
15. Outdoor main PCB fault (last resort)
16. Discharge temperature exceeding 105°C indicates high compressor thermal load

Where to start

1. Verify 3-phase power supply phase sequence is correct. Check that A, B, C terminals match compressor phase sequence requirements. Verify all power supply terminals are securely fastened. Check power supply equipment for abnormalities.
2. Step 1: Check if phase sequence of 3-phase power supply is incorrect
3. Step 2: If sequence correct, check if power supply terminals are loose