Midea R32 M thermal Arctic Mono fault HA

Water side heat exchanger water outlet temperature sensor error

Heat pump

What it means

Error code 49. Water side heat exchanger water outlet temperature sensor (Sensor Tw_out) fault detected by user interface and hydronic system main PCB.

Likely causes

  1. Temperature sensor not connected properly or has malfunctioned. Damaged hydronic system main PCB.
  2. Sensor Tw_out circuit fault
  3. Sensor damage or disconnection
  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. Crushed or bent pipe
  13. Blocked EXV
  14. Dirty filter
  15. Hydronic box main PCB fault
  16. Damaged cables between hydronic box main PCB and outdoor unit main PCB
  17. Outdoor unit main PCB fault
  18. Incorrect or abnormal input power supply (N or L)

Where to start

  1. Identify sensor type based on fault code
  2. Locate corresponding port on refrigerant system main PCB for that model
  3. Check connection at identified port

The full answer, free

  • 72 more checks in order
  • The readings and component tests from the manual
  • How to put it right, step by step
  • The manual page for this fault (page 67), right under the answer

Safety: Isolate the outdoor unit and any backup heater, and give the inverter capacitors time to discharge before you open the electrics. Anything on the refrigerant circuit needs F-gas certification.

From the Midea manual for the R32 M thermal Arctic Mono. Check the model on the data plate before you order parts.

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