Mitsubishi Electric MSZ-EF VE Air Conditioners
12 fault codes documented
Left lamp flashes 0.5-second ON, 0.5-second OFF — Miswiring or serial signal error
The indoor unit's left Operation Indicator lamp flashes with a rapid 0.5-second on and 0.5-second off pattern. This indicates that the indoor and outdoor units are not operating and the serial signal from the outdoor unit is not being received. It can also occur if the indoor unit was previously connected to a non-low-standby-power outdoor model and is now connected to a low-standby-power model.
Left lamp flashes 14 times — Other abnormality detected
The left Operation Indicator lamp flashes fourteen times, followed by a 2.5-second off period. This indicates that an abnormality not specifically covered by the other codes has been detected within the system.
Left lamp flashes 2 times — Indoor coil or room temperature thermistor error
The left Operation Indicator lamp flashes twice, followed by a 2.5-second off period. This indicates an issue with either the indoor coil thermistor or the room temperature thermistor, suggesting a short or open circuit in one of these temperature sensors.
Left lamp flashes 3 times — Indoor fan motor error
The left Operation Indicator lamp flashes three times, followed by a 2.5-second off period. This indicates that the rotational frequency feedback signal from the indoor fan motor is not being emitted during operation, meaning the fan motor is not functioning correctly or has stopped.
Left lamp flashes 4 times — Indoor control system error
The left Operation Indicator lamp flashes four times, followed by a 2.5-second off period. This signifies that the unit cannot properly read data from the nonvolatile memory of the indoor electronic control P.C. board, indicating an internal system error.
Left lamp flashes 5 times — Outdoor power system error
The left Operation Indicator lamp flashes five times, followed by a 2.5-second off period. This indicates that the compressor has stopped due to overcurrent protection or start-up failure protection three consecutive times within one minute after starting.
Left lamp flashes 6 times — Outdoor thermistors error
The left Operation Indicator lamp flashes six times, followed by a 2.5-second off period. This indicates that the outdoor thermistors (temperature sensors) have shorted or opened circuits during compressor operation, preventing accurate temperature readings.
Left lamp flashes 7 times — Outdoor control system error
The left Operation Indicator lamp flashes seven times, followed by a 2.5-second off period. This indicates that data in the nonvolatile memory of the outdoor unit's inverter P.C. board or outdoor electronic control P.C. board cannot be properly read, signaling an internal control system issue.
Left lamp lights up solid — Outdoor control system error, outdoor unit not operating
The left Operation Indicator lamp on the indoor unit remains continuously lit, and the outdoor unit does not operate. This indicates that the unit cannot properly read data in the nonvolatile memory of the outdoor unit's inverter P.C. board or outdoor electronic control P.C. board.
Unit not operating properly or connecting to new outdoor unit — Memorized abnormal condition
The air conditioner may not operate correctly or may have issues connecting to a new low-standby-power outdoor unit if a previous abnormal condition is still memorized. It's crucial to clear the memory after repairs or when changing outdoor unit types.
Failure Recall Mode active: Operation Indicator lamp blinks 0.5s ON/OFF with beeps — General indoor unit abnormality
When the failure mode recall function is activated, if the indoor unit's Operation Indicator lamp blinks at 0.5-second intervals with matching beeps, it indicates a general abnormality within the indoor unit. This signal helps in confirming that an indoor unit fault has been memorized.
Failure Recall Mode active: Operation Indicator lamp stays ON for 3 seconds then blinks 0.5s ON/OFF (no beeps) — General outdoor unit abnormality
When the failure mode recall function is activated, if the indoor unit's Operation Indicator lamp first stays ON for 3 seconds without a beep, and then blinks at 0.5-second intervals, it signals a general abnormality in the outdoor unit. This helps confirm an outdoor unit fault has been memorized.