Midea R32 M thermal Arctic Mono fault EC

What it means

Balance tank sensor Tbt2 error (serial number 13). Displayed on user interface and refrigerant system main PCB.

Likely causes

1. Sensor Tbt2 disconnected, sensor malfunction, wiring break, PCB connection issue
2. Sensor Tbt2 fault
3. Sensor wiring fault
4. Main board fuse damaged/blown
5. Insufficient refrigerant caused by refrigerant leakage
6. Low pressure side blocked by crushed or bent pipe, blocked EXV, or dirty filter
7. Poor air side heat exchanger heat exchange in heating or DHW mode
8. Insufficient water flow rate in cooling mode
9. Outdoor main PCB fault (last resort)
10. Inverter module damaged
11. Discharge temperature exceeding 105°C indicating high compressor load or high ambient/system conditions
12. Hydronic box main PCB fault
13. Damaged cables between hydronic box main PCB and outdoor unit main PCB
14. Outdoor unit main PCB fault
15. Incorrect or abnormal input power supply (N or L)
16. Abnormal system state detected requiring compressor protection
17. Set temperature reached during normal operation

Where to start

1. Check sensor Tbt2 connection, measure sensor resistance, verify wiring continuity, test sensor response
2. Check solar signal input SL1, SL2 wiring per Method1/2/3 configuration
3. Verify zone pump wiring P_s, P_zb terminals