Fault Codes / Mitsubishi Heavy

43 codes

KX / FD

• E1 — Communication error indoor ↔ remote controller.
• E10 — Too many indoor units on one remote controller (max 16).
• E11 — Remote controller detects multiple masters.
• E12 — Address setting error of indoor units by mixed setting method.
• E14 — E14 = master/slave configuration error — wrong SW5 dip-switch setting on indoor PCB, or faulty control wiring (X/Y/Z) between master/slave units. NOT 'duplicate master outdoor-unit address' (that's E31).
• E16 — E16 = indoor fan motor fault (motor faulty/speed below threshold). NOT 'too many indoor units/capacity exceeded' (that's E43).
• E18 — Address setting error of master and slave indoor units.
• E19 — Indoor unit operation check / drain pump motor check mode anomaly.
• E2 — Duplicated indoor address.
• E20 — Indoor DC fan motor rotation speed anomaly.
• E28 — Sensor within the remote controller faulty.
• E3 — Incorrect outdoor unit address setting.
• E30 — Indoor/outdoor unit connection error.
• E31 — E31 = duplicate indoor unit address (U00–U47) or outdoor unit address setting error — NOT a generic 'outdoor unit control fault (U47)'; U47 is just the upper bound of the address range.
• E32 — Open phase / wrong L1-L2-L3 phase sequence.
• E35 — Poor sensor connector on outdoor PCB.
• E36 — Discharge temperature protection (too high).
• E37 — Outdoor subcooling coil temperature sensor anomaly (Tho-SC, -H) — sensor wire breakage.
• E38 — Outdoor air temperature sensor (Tho-A) fault.
• E39 — Discharge temperature sensor (Tho-D) fault.
• E40 — High pressure fault.
• E41 — E41 = inverter power transistor overheat, NOT overcurrent protection (that's E42, a separate code).
• E42 — Abnormally high compressor current (CT).
• E43 — Excessive number of indoor units connected / excessive total capacity (site setting error).
• E45 — Inverter PCB / outdoor PCB communication error.
• E47 — Inverter overvoltage.
• E48 — Outdoor DC fan motor abnormality
• E49 — Low pressure protection (suction too low).
• E5 — Communication error during operation.
• E53 — Suction pipe thermistor (Tho-S) disconnected/faulty.
• E54 — E54 covers BOTH the high-pressure sensor (PSH, 2 flashes) AND the low-pressure sensor (PSL, 1 flash), distinguished by the LED flash count.
• E55 — Compressor dome thermistor (Tho-C) disconnected/faulty.
• E56 — Heat dissipation fins (heat sink) temperature sensor anomaly (Tho-P1, P2) — sensor wire breakage.
• E58 — Anomalous compressor by loss of synchronism.
• E59 — Compressor start failure (CM1/CM2)
• E6 — E6 is a sensor fault at the indoor heat exchanger (ThIR/Thi-R sensor open/short, out-of-range resistance, or loose PCB connector) — NOT 'indoor unit loses communication with outdoor unit' (that belongs to Mitsubishi ELECTRIC, a different brand).
• E60 — Compressor position detection error.
• E61 — Communication error between the master unit and slave units.
• E63 — Emergency stop of indoor unit (external contact).
• E7 — E7 is a sensor fault at the indoor return/suction sensor (ThIA) — open or short circuit, or poor PCB connector. NOT 'outdoor unit: signal loss from indoor unit'.
• E75 — Communication error (defective communication) — SL1N-E module.
• E8 — E8 = heating overload (abnormally high indoor heat exchanger temperature) or indoor heat exchanger sensor (ThIR) fault/short; drain pump/float switch issues also possible. NOT 'address collision/connection error' (that's E2/E12/E46).
• E9 — Drain water level abnormality (float switch)