M thermal Mono
202004 79
4.18 P4 Troubleshooting
Digital display output
Description
Discharge temperature protection.
When the compressor the discharge temperature rises above 115°C, the system displays P4 protection and M thermal
Mono stops running. When the discharge temperature falls below 95°C, P4 is removed and normal operation
resumes.
Error code is displayed on refrigerant system main control board for refrigerant system and user interface.
Possible causes
Temperature sensor error
High pressure side blockage.
Poor condenser heat exchange.
Main PCB damaged.