Mitsubishi PWFY air conditioner fault codes

During the operation of air conditioners, especially if there is no service care, a number of typical problems requiring immediate care inevitably arise. Some of the problems can be fixed using the troubleshooting table. It contains a list of the main breakdowns of this type of equipment, as well as options for fixing the problems.

4031Comms fault between boards - check between control board an inverter board
4035Comms fault between boards - check between control board an fan board
1102High compressor discharge temperature - discharge temp has exceeded 115°C or more -
check if short of refrigerant or discharge thermistor
1301Low pressure fault - low pressure sensor sensing less than 1 bar immediately before starting
1302High pressure fault - check system pressure exceded 32.3 bar , check high pressure sensor
(63HS) against gauge pressure
2000Pump interlock error - pump interlock open whilst system in operation
2134Abnormal water temperature (TH6) has exceded 85°C
2135Water source heat exchanger frozen (TH6) or (TH8) reading 2°C
4102Open phase fault - check power supply and noise filter for loss of phase, check wiring and fuses
4115Power supply abnormal - check power , fuses, connections and PCB
4220108Low inverter board BUS voltage - less than 200Vdc is detected during in inverter operation -
check mains supply
42201Bus voltage error PAM damage - replace the inverter board
4220109High bus voltage Vdc>380v - check power supply and possible faulty inverter board
4220121Replace inverter board
4230High temperature (85°C) on heat sink on inverter - check for blockages in air duct, failure of INV fan
failure of INV fan or failure of thermistor (THHS)
4250Over current protection - inverter IPM problem or compressor lock - check inverter balance
4250ACCT sensor over current detection 34.5A peak or 16A rms is detected - check the compressor
for failure, or possible inverter board failure
5102Thermistor TH22 failure
5103Thermistor TH13 or TH23 failure
5104Thermistor TH11 failure
5106Thermistor TH6 failure
5108Thermistor TH8 failure
5110Thermistor THHS failure
5201High pressure sensor fault - check the system pressure is >1 bar ,
check the operation of 63HS high pressure transducer
5202Pressure sensor fault
5301Current sensor fault, ACCT or DCCT - check inv. error details
5301115Low output current <1.5A rms whilst the inverter is in operation