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 supply
3. Power supply terminals loose
4. Power supply abnormal
5. Main PCB damaged
6. Insufficient refrigerant caused by refrigerant leakage
7. Low pressure side blocked by crushed or bent pipe, blocked EXV, or dirty filter
8. Poor air side heat exchanger heat exchange in heating or DHW mode
9. Insufficient water flow rate in cooling mode
10. Outdoor main PCB fault (last resort)
11. Inverter module damaged
12. Main board fuse damaged/blown
13. Hydronic box main PCB fault
14. Damaged cables between hydronic box main PCB and outdoor unit main PCB
15. Outdoor unit main PCB fault
16. Incorrect or abnormal input power supply (N or L)

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. Check if the phase sequence of the 3-phase power supply is incorrect
3. Check if some power supply terminals are loose