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Mitsubishi City Multi VRF air conditioning systems are famed for their ultra-quiet noise levels, higher savings on installation and running costs, and a significantly reduced footprint.
But much like other air conditioner brands, your mitsubishi city multi air conditioner may, on occasion, malfunction.
Now, a good place to start your troubleshooting when a fault occurs is looking for error codes- and the great thing is that some of the most common mitsubishi city multi error codes can be resolved by performing basic DIY maintenance.
This article lists the most prevalent mitsubishi city multi error codes and their meaning- plus tips to help you fix the problem depending on the exact model you own.
Read through the fault codes- solving the problem causing your air conditioner not to operate properly may be a lot easier than you think:
Mitsubishi City Multi Error Codes plus troubleshooting tips
With many mitsubishi city multi air conditioner models, fault codes are made up of 3 or 4 digits.
Here is a detailed list of mitsubishi city multi error codes, possible meanings, and potential troubleshooting steps (for some):
Mitsubishi City Multi Error Codes- full list
Error code 403 (Mitsubishi City Multi R22, R4O7c, and R410A models)
Meaning: Communication fault between boards
Recommended fix: Check transformer, bus voltage, and inter-connecting cables. Also check inverter error detail for which 2 boards.
Error code 1102 (Mitsubishi City Multi R22, R4O7c, and R410A models)
Meaning: Compressor discharge temperature high (has exceeded 110°C).
Recommended fixes: refrigerant may need to be refilled (could be insufficient). In addition, check discharge thermistor.
Mitsubishi city multi error code 1111, 1112, 1113 (Mitsubishi City Multi R22, R4O7c)
Meaning: Low pressure/temperature problem
Recommended fixes: check thermistors (TH2, TH3, TH4). Also check gas charge, the indoor fan, heat exchanger, and filter
Error code 1202 (Mitsubishi City Multi R22, R4O7c, R410A)
Meaning: Preliminary fault to error code 1102
Error code 1204 (Mitsubishi City Multi R410A)
Meaning: Preliminary heat exchanger gas temperature sensor problem
Recommended fixes: check thermistors 10a & 10b
Error code 1205 (Mitsubishi City Multi R22, R4O7c, R410A)
Meaning: Preliminary thermistor issue(TH5)
Error code 1211 (Mitsubishi City Multi R22, R4O7c)
Meaning: Preliminary thermistor issue(TH2)
Error code 1214 (Mitsubishi City Multi R22, R4O7c, R410A)
Meaning: Preliminary thermistor issue(THHS)
Error code 1216 (Mitsubishi City Multi R22, R4O7c, R410A)
Meaning: Preliminary thermistor issue(TH7)
Error code 1217 (Mitsubishi City Multi R22, R4O7c, R410A)
Meaning: Preliminary thermistor issue(TH8)
Error code 1219 (Mitsubishi City Multi R22, R4O7c)
Meaning: Preliminary thermistor issue(TH9)
Error code 1221 (Mitsubishi City Multi R22, R4O7c, R410A)
Meaning: Preliminary thermistor issue(TH6)
Error code 1243 (Mitsubishi City Multi R4O7c)
Meaning: Preliminary thermistor issue(TH10)
Error code 1301 (Mitsubishi City Multi R4O7c)
Meaning: Low pressure fault(63L operation)-low pressure sensor could be sensing less than 1 bar immediately before starting.
Error code 1302 (Mitsubishi City Multi R22, R4O7c)
Meaning: High pressure issue – check pressure in the system for more than 29 bar(R407c)/38 bar(R410A).
Recommended fixes: Check the high pressure sensor against the gauge pressure
Error code 1368 (Mitsubishi City Multi R22, R4O7c)
Meaning: Pressure sensor issue(PS1) at BC
Recommended fixes: Compare the pressure reading on SW1 (on O/C)
Error code 1370 (Mitsubishi City Multi R22, R4O7c)
Meaning: Pressure sensor fault(PS3) at BC
Recommended fixes: compare the pressure reading on SW1(at O/C)
Error code 1402(Mitsubishi City Multi R410A)
Meaning: Preliminary issue to 1302
Error code 1500 (Mitsubishi City Multi R22, R4O7c, R410A)
Meaning: System overcharge(Abnormal low compressor super-heat ).
Recommended fixes: discharge thermistor TH4
Error code 1501 (Mitsubishi City Multi R22, R4O7c)
Meaning: High compressor shell temperature
Recommended fixes: check for potential shortage of gas. Can also be due to insufficient indoor index running(comms room units).
Error code 1505 (Mitsubishi City Multi R22, R4O7c)
Meaning: Abnormal suction pressure(generated when low pressure sensor detects a vacuum)
Recommended fixes: check for blockage or a closed valve. Also check for sensor fault
Error code 2500 (Mitsubishi City Multi R22, R4O7c, R410A)
Meaning: there is lack of waterflow on the water circuit
Mitsubishi city multi error code 2502 (R22, R4O7c, R410A)
Meaning: I/C has water level in the drip tray
Troubleshooting steps: check for open/closed circuit(temperature sensors). Also check if the pump is operating correctly.
Error code 2503 (R22, R4O7c, R410A)
Meaning: I/C has water level in the drip tray
Troubleshooting steps: check for closed circuit(on float switch). Also check if the pump is running properly.
Error code 2600 (R22, R410A)
Meaning: Water is leaking from humidifier
Error code 4102 ( R410A)
Meaning: Open phase fault
Troubleshooting steps: Check the power supply as well as noise filter for possible loss of phase. Also check the wiring and fuses.
Error code 4103 (R22, R4O7c, R410A)
Meaning: Reverse phase issue.
Troubleshooting steps: -check phase rotation. Also check if there is loss of phase (through noise filter). Finally check if there is a blown fuse or if the high pressure switch is open (at power on)
Error code 4108 ( R410A)
Meaning: Over current protection (on DOL compressor)
Troubleshooting steps: Check the following parts: power supply, contactor, and compressor
Error code 4115 (R22, R4O7c, R410A)
Meaning: power supply abnormal
Troubleshooting steps: – check power, connections, fuses, and PCB
Error code 4116 (R22, R4O7c, R410A)
Meaning: Fan motor abnormal
Troubleshooting steps: check fan motor as well as the board (relates to the indoor unit/Lossnay unit)
Error code 4210 ( R22)
Meaning: Compressor over current fault
Troubleshooting steps: check the inverter balance. Also check the compressor and inverter.
Error code 4220 (R4O7c, R410A)
Meaning: Low BUS voltage on inverter board (Less than 289VdcDC detected).-
Troubleshooting steps: check mains supply
Error code 4225 (R410A)
Meaning: Low DC voltage detected on Vdc on the fan inverter
Troubleshooting steps: check the CNVdc for 300Vdc (on diode stack). Also check power supply(mains) to your outdoor unit
Error code 4230 (R22, R4O7c, R410A)
Meaning: High temp on heat sink (on inverter)
Troubleshooting steps: check for blockages (in air duct). Also check if the INV fan has failed. Finally test if the thermistor has failed.
Error code 4235 (R410A)
Meaning: Fan inverter heat sink overheating protection due to reduced airflow through the heat sink or a fan motor fault. This could also indicate THHS thermistor issue.
Error code 4240 (R22, R4O7c, R410A)
Meaning: Over current protection- high current may have been detected for 10 (or more) minutes.
Possible fixes: check inverter balance. Also try to identify what may be causing reduced airflow through the heat sink
Error code 4245 (R410A)
Meaning: Over current protection due to potential ACCT current sensor problem (Should read 280ohms between pins 1 and 2 and across the pins 3 and 4.
Error code 4250 (R410A)
Meaning: Over current protection (may be caused by Inverter IPM fault/Compressor lock)
Troubleshooting steps: check inverter balance
Error code 4255 (R410A)
Meaning: Inverter cooling fan issue.
Troubleshooting steps: if using high static fan, you should check that the SW3-9 is on.
Error code 4260 (R4O7c, R410A)
Meaning: Preliminary overheat protection (on inverter heat sink) probably caused by reduced airflow through the heat sink. The issue can also be due to a fan motor problem or THHS thermistor fault.
Error code 5101, 5102, 5103, 5104 (R22, R4O7c, R410A)
Meaning:Thermistor fault (at indoor/outdoor unit)
Troubleshooting steps: check error code address
Error code 5105 (R22, R4O7c, R410A)
Meaning:TH5 open/short circuit
Troubleshooting steps: The TH may be disconnected from the board. Check.
Error code 5106 (R22, R4O7c, R410A)
Meaning:TH6 open/short circuit
Troubleshooting steps: The TH may be disconnected from the board. Check.
Error code 5107 (R22, R4O7c, R410A)
Meaning:TH7 open/short circuit
Troubleshooting steps: The TH may be disconnected from the board. Check.
Error code 5108 (R22, R4O7c)
Meaning:TH8 open/short circuit
Troubleshooting steps: The TH may be disconnected from the board. Check.
Error code 5109 (R4O7c)
Meaning:TH9 open/short circuit
Troubleshooting steps: The TH may be disconnected from the board. Check.
Error code 5110 (R22, R4O7c, R410A)
Meaning:TH10 open/short circuit
Troubleshooting steps: The TH may be disconnected from the board. Check.
Error code 5111 (R22, R410A)
Meaning: BC box thermistor fault (due to TH11 open/short circuit or disconnection from board/pipe)
Error code 5112 (R22, R4O7c, R410A)
Meaning: BC box thermistor fault (due to TH10 open/short circuit or disconnection from board/pipe)
Error code 5113 (R22), Error code 5114 (R22)
Meaning: BC box thermistor fault (due to TH open/short circuit or disconnection from board/pipe)
Error code 5115 (R22, R410A)
Meaning: BC box thermistor fault (due to TH15 open/short circuit or disconnection from board/pipe)
Error code 5116 (R22, R410A)
Meaning: BC box thermistor fault (due to TH16 open/short circuit or disconnection from board/pipe)
Error code 5201 (R22, R4O7c, R410A)
Meaning: Pressure sensor problem (outdoor unit or BC box)
Troubleshooting steps: check error code address or SW 1 pressure sensor readings.
Error code 5202 (R22)
Meaning: Pressure sensor problem (PS2) in BC box
Error code 5203 (R22, R4O7c, R410A)
Meaning: Pressure sensor problem (outdoor unit or BC box)
Troubleshooting steps: check error code address or SW 1 pressure sensor readings.
Error code 5301 (R4O7c, R410A)
Meaning: Current sensor fault (or ACCT/DCCT)
Troubleshooting steps: check inverter error details
Error code 5401 (R410A)
Meaning:Temperature sensor fault
Troubleshooting steps: check CN 30 for humidity sensor
Error code 5701 (R410A)
Meaning: float switch connector loose
Troubleshooting steps: check switch. Also check CN4F (on the indoor unit)
Error code 6201 (R410A)
Meaning: TB7 transmission line has communication error
Troubleshooting steps: check for abnormality in voltage/short
Error code 6202 (R410A)
Meaning: Transmission processor hardware fault
Troubleshooting steps: check for short/noise on M-Net cable
Error code 6600 (R22, R4O7c, R410A)
Meaning: Repeat address issue -it means the same address has been assigned two (or more units)
Troubleshooting steps: the repeated address need to be corrected
Error code 6601 (R410A)
Meaning: Polarity setting fault (there is no voltage –or there is a short circuit -on m-net transmission line)
Error code 6602 (R22, R4O7c, R410A)
Meaning: Hardware error on transmission processor. It may also indicate noise interference or even a polarity problem on TB 7.
Error code 6603 (R22, R4O7c, R410A)
Meaning: Bus circuit busy.
Troubleshooting steps: check if the indoor unit (or anything else) is wired into TB7 (instead of TB3) and correct the wiring error
Mitsubishi city multi error code 6607 /mitsubishi vrf error code 6607 (R22, R4O7c, R410A)
Meaning: Communication issue (no response is coming from unit whilst the system is operational)
Error code 6608 (R22, R4O7c, R410A)
Meaning: Communication error -there is loss of voltage (or noise) entering into the transmission line
Error code 6831 (R410A)
Meaning:MA R/C communication fault
Troubleshooting steps: check connections on TB 15. You can also check that the controller had been removed while the I /C was powered
Error code 6832, 6833, 6834 (R410A)
Meaning:MA controller communication fault
Troubleshooting steps: check cable length – should not be bigger than 500m. Also, check for proper connection and that the proper type of cable has been used.
Error code 7100 (R22, R4O7c, R410A)
Meaning: Over capacity
Error code 7101 (R22, R4O7c, R410A)
Meaning: Capacity setting issue – SW2 set wrong (on indoors), SW5 set wrong on YHMA outdoor (SW3-10 on older kits)
Mitsubishi city multi error code 7102 (R22, R4O7c, R410A)
Meaning: It may point to an error in the number of units you have connected or indicate loss of MNet voltage (short/break). It may also mean there is no power to the BC or even wrong SW 5 setting on box (or even wrong box type).
Error code 7105 (R22, R4O7c, R410A)
Meaning: Address setting issue – OC/BC addressed incorrectly
Error code 7106 (R4O7c, R410A)
Meaning: Attribute setting fault (SW3-1 setting on GUF)
Error code 7107 (R4O7c, R410A)
Meaning: Port setting issue- check if there is too much capacity on one port. Also check wiring, SW2 setting, SW14 setting (it could be wrong too) or even for wrong units (on a box if using multiple boxes)
Wrap up
This ‘mitsubishi city multi error codes check list’ provides an easy-to-use reference guide on all mitsubishi city multi error codes across the company’s product range.
More troubleshooting ideas and guidance can be found on the trouble-shooting section of your specific model’s service manual.
Be sure to contact a qualified HVAC technician if your aircon need advanced repair(s).
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