Indoor unit failure mode table | Mitsubishi Electronics MSZ-A24NA

2. Indoor unit failure mode table

Left lamp of OPERATION	Abnormal point	Condition	Correspondence
INDICATOR lamp	(Failure mode)	Condition	Correspondence
INDICATOR lamp	(Failure mode)

Not lighted	Normal	–	–

1-time flash	Room temperature	The room temperature thermistor short	Refer to the characteristics of the room
1-time flash	Room temperature	or open circuit is detected every 8	Refer to the characteristics of the room
every 0.5-second	thermistor	or open circuit is detected every 8	temperature thermistor (8-7.).
every 0.5-second	thermistor	seconds during operation.	temperature thermistor (8-7.).
		seconds during operation.

2-time flash		The indoor coil thermistor short or open	Refer to the characteristics of the main
2-time flash	Indoor coil thermistor	circuit is detected every 8 seconds during	indoor coil thermistor, the sub indoor coil
2.5-second OFF	Indoor coil thermistor	circuit is detected every 8 seconds during	indoor coil thermistor, the sub indoor coil
2.5-second OFF		operation.	thermistor (8-7.).
		operation.	thermistor (8-7.).

3-time flash	Serial signal	The serial signal from outdoor unit is	Refer to 8-6.D"How to check mis-wiring
2.5-second OFF	Serial signal	not received for a maximum of 6 minutes.	and serial signal error".
2.5-second OFF		not received for a maximum of 6 minutes.	and serial signal error".

11-time flash		The rotational frequency feedback	Refer to 8-6.A"Check of indoor fan
11-time flash	Indoor fan motor	signal is not emit during the 12 seconds the	Refer to 8-6.A"Check of indoor fan
2.5-second OFF	Indoor fan motor	signal is not emit during the 12 seconds the	motor".
2.5-second OFF		indoor fan operation.	motor".
		indoor fan operation.

12-time flash		It cannot properly read data in the	Replace the indoor electronic control
12-time flash	Indoor control system	nonvolatile memory of the indoor electronic	Replace the indoor electronic control
2.5-second OFF	Indoor control system	nonvolatile memory of the indoor electronic	P.C. board.
2.5-second OFF		control P.C. board.	P.C. board.
		control P.C. board.

NOTE : Blinking patterns of this mode differ from the ones of Troubleshooting check table (8-4.).

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