Service Manual
Installation and Maintenance
28
No.
Malfunction
Name
Display Method of Indoor Unit
Display Method of Outdoor
Unit
A/C Status
Possible Causes
Dual-8
Code
Display
Indicator Display (during
blinking, ON 0.5s and OFF
0.5s)
Indicator has 3 kinds of
display status and during
blinking, ON 0.5s and OFF
0.5s
Operation
Indicator
Cool
Indicator
Heat
Indicator
Yellow
Indicator
Red
Indicator
Green
Indicator
16
Outdoor
condenser
temperature
sensor is
open/short
circuited
F4
OFF 3S
and blink
4 times
OFF 1S
and
blink
5 times
During cooling and
drying operation,
compressor stops
while indoor fan
will operate;During
heating operation,
the complete unit will
stop operation.
Outdoor temperature
sensor hasnt been
connected well or
is damaged. Please
check it by referring
to the resistance
table for
temperature sensor)
17
Outdoor
discharge
temperature
sensor is
open/short
circuited
F5
OFF 3S
and blink
5 times
OFF 1S
and
blink
7 times
During cooling and
drying operation,
compressor will sop
after operating for
about 3 mins,
while indoor fan
will operate;During
heating operation, the
complete unit will stop
after operating for
about 3 mins.
1.Outdoor
temperature sensor
hasnt been
connected well or is
damaged. Please
check it by referring
to the resistance
table for temperature
sensor)
2.The head of
temperature sensor
hasnt been inserted
into the copper tube
18
Limit/
decrease
frequency
due to
overload
F6
OFF 3S
and blink
for 6
times
OFF 1S
and
blink
3 times
All loads operate
normally,while
operation frequency
for compressor is
decreased
Refer to the
malfunction analysis
(overload, high
temperature
resistant)
19
Decrease
frequency
due to
overcurrent
F8
OFF 3S
and blink
8 times
OFF 1S
and
blink
once
All loads operate
normally,while
operation frequency
for compressor is
decreased
The input supply
voltage is too low;
System pressure is
too high and
overload
20
Decrease
frequency
due to
high air
discharge
F9
OFF 3S
and blink
9 times
OFF 1S
and
blink
twice
All loads operate
normally, while
operation frequency
for compressor is
decreased
Overload or
temperature is too
high;Refrigerant
is insufficient;
Malfunction of electric
expansion
valve (EKV)
21
Limit/
decrease
frequency
due to
antifreezing
FH
OFF 3S
and blink
2 times
OFF 3S
and blink
2 times
OFF 1S
and
blink
4 times
All loads operate
normally, while
operation frequency
for compressor is
decreased
Poor air-return in
indoor unit or fan
speed is too low