Mitsubishi Heavy Industries FDC112KXEN6 Technical Manual page 325

Error code
Remote controller: None
7-segment display:
1. Applicable model
All models
2. Error detection method
3. Condition of error displayed
4. Presumable cause
Note:
LED Green Red
– –
Indoor
– –
Outdoor
5. Troubleshooting
Diagnosis
From 1/3
[Unit side]
YES
Does noise/vibration
occur when the cooling/
heating operation is
performed
normally?
NO
To 3/3
321
–
Content
Excessive noise/vibration (2/3)
Are the pipes
contacting with the
casing?
NO
Is continuous
hissing or roaring sound
occurred?
NO
Are hissing sounds
occurred at the startup or
stopping?
NO
Is blowing
sound occurred at
the start/stop of defrost
operation during
heating mode?
NO
Is cracking noise
occurred during heating
operation?
NO
Is hissing
noise occurred
during cooling operation
or after operation
stopped?
NO
–
Countermeasure
Rearrange the piping to
YES avoid contact with the
casing.
Noise/vibration is
generated when the
refrigerant gas or liquid
YES flows through inside of
piping of air-conditioner.
It is likely to occur
particularly during cooling
or defrosting in the heating
mode. It is normal.
The noise/vibration occurs
YES
when the refrigerant starts
or stops flowing. It is
normal.
When the defrosting starts
or stops during heating
mode, the refrigerant flow
is reversed due to switching
4-way valve. This causes
YES
a large change in pressure
which produces a blowing
sound. It may accompany
also the hissing sounds as
mentioned above. This is
normal.
After the start or stop of
heating operation or during
YES
defrosting, abrupt changes
in temperature cause resin
parts to shrink or expand.
This is normal.
It is the sound produced
by the drain pump that
discharges drain from the
indoor unit. The pump
YES
continues to run for 5
minutes after stopping the
cooling operation. This is
normal.
Apply the damper sealant
at places considered to
be the sources such as
the pressure reducing
mechanism (expansion
valve), capillary, etc.