For MTBU-12HRDN1-M, MTBU-18HRDN1-M, MCA2U-12HRFN1-M, MCA2U-18HRFN1-M, MUBU-
12HRFN1-M, MUBU-18HRFN1-M:
Open or short circuit of T1 temperature sensor
Open or short circuit of T2 temperature sensor
Communication malfunction between indoor and
outdoor units
Indoor EEPROM malfunction
Open or short circuit of T3 or T4 temperature sensor
or outdoor EEPROM malfunction
Outdoor fan has been out of control
Indoor fan speed has been out of control
Temperature protection of compressor top.
Outdoor unit over-current protection
Inverter compressor drive protection
★ flash at 2.5Hz, light, X extinguished, , ◎flash at 0.5Hz
Note: Digital display is only available for duct type.
Oasis series:
Indoor EEPROM malfunction
Communication malfunction between indoor and outdoor units
Indoor fan speed malfunction.
Indoor room temperature sensor open or short circuit.
Evaporator coil temperature sensor open or short circuit.
Outdoor temperature sensor open or short circuit.
Condenser coil temperature sensor open or short circuit.
Compressor discharge pipe sensor open or short circuit.
Outdoor EEPROM malfunction
Outdoor fan has been out of control
Indoor unit coil outlet temp. sensor open or short circuit.