M thermal Mono
202004 57
4.4 E2 Troubleshooting
Digital display output
Description
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.
Possible causes
Communication wires between outdoor unit and user interface not connected properly.
Communication wiring X Y E terminals misconnected.
Loosened wiring within electric control box.
Interference from high voltage wires or other sources of electromagnetic radiation.
Damaged main PCB or electric control box communication terminals block.