Error Codes: Central Ducted System – MRCOOL

An error code is a way for an HVAC system (like a mini-split or central unit) to communicate that something isn’t working properly.
Instead of just shutting down with no explanation, the system will flash a specific code — usually letters and numbers — on a display or indicator light.

Each error code points to a specific issue, like:

Electrical problems
Sensor malfunctions
Communication failures between components
Refrigerant pressure issues
Motor faults
Temperature problems

Central Ducted Condenser:

Model

CENTRAL-18-HP-C-230-25

CENTRAL-24-HP-C-230-25

CENTRAL-30-HP-C-230-25

CENTRAL-36-HP-C-230-00

CENTRAL-48-HP-C-230-00

CENTRAL-60-HP-C-230-00

Diagnostic Codes:

Error Code:	Error:
EH 00	Indoor PCB
EL 01	Indoor PCB, Outdoor PCB, or Reactor
EH 03	Indoor PCB, Indoor fan motor
EH 60	Indoor PCB, T1 sensor
EH 61	Indoor PCB, T2 Sensor
EH 62	Indoor PCB, T2B Sensor
EH 65	Indoor PCB, T2A Sensor
EL 0C	Indoor PCB, Additional refrigerant
EH 0E	Indoor PCB, Water-level switch, or Water pump
EC 53	Outdoor PCB, T4 Sensor
EC 54	Outdoor PCB, TP Sensor
EC 51	Outdoor PCB
EC 5C	Outdoor PCB, Pressure sensor
EC 52	Outdoor PCB, T3 Sensor
EC 07/71/72/73	Outdoor PCB, Outdoor fan motor
PC 00	Outdoor PCB, Outdoor fan motor, Compressor, IPM module board
PC 01	Outdoor PCB, Reactor, IPM module board
PC 02	Outdoor PCB, Outdoor fan motor, IPM module board
PC 04	Outdoor PCB, Outdoor fan motor, Compressor, IPM module board
PC 03	Outdoor PCB, Low pressure protector, Additional refrigerant
EL 16	Outdoor PCB, Data adapter board
EH 0b	Indoor PCB, Data adapter board
PC 06	Outdoor PCB, TP Sensor, High pressure valve, Additional refrigerant
PC 08/44/49	Outdoor PCB, Outdoor fan motor, Reactor, IPM module board
PC 0A	Outdoor PCB, Outdoor fan motor, T3 Sensor, Additional refrigerant
PC 0F	Outdoor PCB, Reactor,
PC 41	Outdoor PCB
PC 43	Outdoor PCB, Compressor
PC 10/11/12	Outdoor PCB, Reactor, IPM module board
PC 30	Outdoor PCB, Outdoor fan motor, High pressure protector
PC 31	Outdoor PCB, Low pressure protector, Additional refrigerant
PC 40	Outdoor PCB, IPM module board, Electric control box

・・・──────────────────────────────・・・

Central Ducted Air Handler:

Model

CENTRAL-18-HP-MUAH-230-25

CENTRAL-24-HP-MUAH-230-25

CENTRAL-30-HP-MUAH-230-25

CENTRAL-36-HP-MUAH-230-00

CENTRAL-48-HP-MUAH-230-00

CENTRAL-60-HP-MUAH-230-00

Diagnostic Codes:

Error Code:	Error:
EH 00	Indoor unit EEPROM parameter error
EL 01	Indoor / outdoor unit communication error
EL 16	Communication malfunction between adapter board and outdoor main board
EH 03	The indoor fan speed is operating outside of the normal range(for some models)
EH 60	Indoor room temperature sensor T1 is in open circuit or has short circuited
EH 61	Evaporator coil temperature sensor T2 is in open circuit or has short circuited
EH 62	Evaporator coil temperature sensor T2B is in open circuit or has short circuited
Eh 65	Evaporator coil temperature sensor T2A is in open circuit or has short circuited
EL 0C	Refrigerant Leakage Detection(for some models
EH 0b	Communication error between indoor two chips
EH 0E	Water-level alarm malfunction
EC 53	Outdoor room temperature sensor T4 is in open circuit or has short circuited
EC 52	Condenser coil temperature sensor T3 is in open circuit or has short circuited
EC 54	Compressor discharge temperature sensor TP is in open circuit or has short circuited
EC 56	Evaporator coil outlet temperature sensor T2B is in open circuit or has short circuited(for freematch indoor units)
EC 51	Outdoor unit EEPROM parameter error
EC 07	The outdoor fan speed is operating outside of the normal range(for some models)
PC 00	IPM malfunction or IGBT over-strong current protection
PC 01	Over voltage or over low voltage protection
PC 02	Top temperature protection of compressor or High temperature protection of IPM module
PC 04	Inverter compressor drive error
PC 03	Low pressure protection (for some models)
EC 0d	Outdoor unit malfunction
PC 0L	Low ambient temperature protection
FL 09	Mismatch between the new and old platforms

・・・──────────────────────────────・・・

Hyper Heat Condenser:

Model

CENTRAL-24-HP-C-230A00

CENTRAL-36-HP-C-230A00

CENTRAL-48-HP-C-230A00

CENTRAL-60-HP-C-230A00

Diagnostic Codes:

Error Code:	Error:
EH 00	Indoor PCB
EL 01	Indoor PCB, Outdoor PCB, or Reactor
EH 03	Indoor PCB, Indoor fan motor
EH 60	Indoor PCB, T1 sensor
EH 61	Indoor PCB, T2 Sensor
EH 62	Indoor PCB, T2B Sensor
EH 65	Indoor PCB, T2A Sensor
EL 0C	Indoor PCB, Additional refrigerant
EH 0E	Indoor PCB, Water-level switch, or Water pump
EC 53	Outdoor PCB, T4 Sensor
EC 54	Outdoor PCB, TP Sensor
EC 51	Outdoor PCB
EC 5C	Outdoor PCB, Pressure sensor
EC 52	Outdoor PCB, T3 Sensor
EC 07/71/72/73	Outdoor PCB, Outdoor fan motor
PC 00	Outdoor PCB, Outdoor fan motor, Compressor, IPM module board
PC 01	Outdoor PCB, Reactor, IPM module board
PC 02	Outdoor PCB, Outdoor fan motor, IPM module board
PC 04	Outdoor PCB, Outdoor fan motor, Compressor, IPM module board
PC 03	Outdoor PCB, Low pressure protector, Additional refrigerant
EL 16	Outdoor PCB, Data adapter board
EH 0b	Indoor PCB, Data adapter board
PC 06	Outdoor PCB, TP Sensor, High pressure valve, Additional refrigerant
PC 08/44/49	Outdoor PCB, Outdoor fan motor, Reactor, IPM module board
PC 0A	Outdoor PCB, Outdoor fan motor, T3 Sensor, Additional refrigerant
PC 0F	Outdoor PCB, Reactor,
PC 41	Outdoor PCB
PC 43	Outdoor PCB, Compressor
PC 10/11/12	Outdoor PCB, Reactor, IPM module board
PC 30	Outdoor PCB, Outdoor fan motor, High pressure protector
PC 31	Outdoor PCB, Low pressure protector, Additional refrigerant
PC 40	Outdoor PCB, IPM module board, Electric control box

・・・──────────────────────────────・・・

Hyper Heat Air Handler:

Model

CENTRAL-24-HP-MUAH230A00

CENTRAL-36-HP-MUAH230A00

CENTRAL-48-HP-MUAH230A00

CENTRAL-60-HP-MUAH230A00

Diagnostic Codes:

Error Code:	Error:
EH 00	Indoor unit EEPROM parameter error
EL 01	Indoor / outdoor unit communication error
EL 16	Communication malfunction between adapter board and outdoor main board
EH 03	The indoor fan speed is operating outside of the normal range(for some models)
EH 60	Indoor room temperature sensor T1 is in open circuit or has short circuited
EH 61	Evaporator coil temperature sensor T2 is in open circuit or has short circuited
EH 62	Evaporator coil temperature sensor T2B is in open circuit or has short circuited
Eh 65	Evaporator coil temperature sensor T2A is in open circuit or has short circuited
EL 0C	Refrigerant Leakage Detection(for some models
EH 0b	Communication error between indoor two chips
EH 0E	Water-level alarm malfunction
EC 53	Outdoor room temperature sensor T4 is in open circuit or has short circuited
EC 52	Condenser coil temperature sensor T3 is in open circuit or has short circuited
EC 54	Compressor discharge temperature sensor TP is in open circuit or has short circuited
EC 56	Evaporator coil outlet temperature sensor T2B is in open circuit or has short circuited(for freematch indoor units)
EC 51	Outdoor unit EEPROM parameter error
EC 07	The outdoor fan speed is operating outside of the normal range(for some models)
PC 00	IPM malfunction or IGBT over-strong current protection
PC 01	Over voltage or over low voltage protection
PC 02	Top temperature protection of compressor or High temperature protection of IPM module
PC 04	Inverter compressor drive error
PC 03	Low pressure protection (for some models)
EC 0d	Outdoor unit malfunction
PC 0L	Low ambient temperature protection
FL 09	Mismatch between the new and old platforms

・・・──────────────────────────────・・・

2nd Gen Hyper Heat:

Model

CENTRAL-24-HP-C-230B00-O

CENTRAL-30-HP-C-230B00-O

CENTRAL-36-HP-C-230B00-O

CENTRAL-48-HP-C-230B00-O

CENTRAL-60-HP-C-230B00-O

Diagnostic Codes:

Error Code:	Error:
EC 07	ODU fan speed out of control
EC 51	ODU EEPROM parameter error
EC 52	ODU coil temperature sensor (T3) error
EC 53	ODU ambient temperature sensor (T4) error
EC 54	Compressor discharge temperature sensor (T4) error
EC 55	ODU IPM module temperature sensor malfunction
EC 57	Refrigerant pipe temperature sensor error
EC SC	Pressure sensor failure
EL 01	IDU & ODU communication error
EL 16	Communication malfunction between adapter board and ODU main board
PC 00	IPM Module Protection
PC 02	Compressor top (or IPM) temperature protection / Refrigerant sensor error
PC 06	Discharge temperature protection of compressor
PC 08	Outdoor overcurrent protection
PC 0A	High temperature protection of condenser
PC 0F	PFC Module Protection
PC 10	ODU low AC voltage protection
PC 11	ODU main control board DC bus high voltage protection
PC 12	ODU main control board DC bus low voltage protection / 341 MCE error
PC 30	System high pressure protection
PC 31	System low pressure protection
PC 40	Communication error between ODU main chip and compressor driven chip
PC 41	Compressor current sampling failure
PC 42	Compressor start failure of outdoor unit
PC 43	ODU compressor lack phase protection
PC 44	ODU zero speed protection
PC 45	ODU IR chip drive failure
PC 46	Compressor speed out of control
PC 49	Compressor overcurrent failure
LC 06	High temperature protection of Inverter Module (IPM)
PH 90	High temperature protection of evaporator
PH 91	Low temperature protection of evaporator

✅ Why Error Codes Matter:
They help technicians, installers, and even homeowners quickly understand where to start troubleshooting without guessing.

✅ Important Tip:
While error codes point you in the right direction, they don’t always tell you the exact part that’s failed — just the general area or type of problem. Further testing is often needed!

Related to

Related articles