Midea R32 M thermal Arctic Mono fault E2

Communication error between outdoor unit and user interface

Heat pump

What it means

Communication error between outdoor unit and user interface. M thermal Mono stops running. Error code is displayed on hydronic system main control board for refrigerant system and user interface.

Likely causes

  1. Loose wiring
  2. Damaged PCB or terminals
  3. Communication wires not connected in daisy chain topology
  4. Damaged main PCB or electric control box communication terminals block
  5. Loose wire connections at communication terminals block
  6. Short circuit, disconnection, or misconnection of communication wires
  7. Communication wires between outdoor unit and user interface not connected properly
  8. Communication wiring X Y E terminals misconnected
  9. Loosened wiring within electric control box
  10. Short circuit in communication wires, disconnected wires, or incorrect wire connections
  11. Loose communication wiring, damaged communication cable, PCB malfunction, shielding issue
  12. Wires not fully inserted into connectors
  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. Step 1: Check communication wire connections between outdoor unit and user interface
  2. Step 3: Inspect electric control box for loosened wiring
  3. Step 5: Inspect main PCB and communication terminals for damage or blockage

The full answer, free

  • 24 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 73), 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.

Other Midea R32 M thermal Arctic Mono fault codes