Service Manual
Installation and Maintenance
27
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
13
Indoor
ambient
temperature
sensor is
open/short
circuited
F1
OFF 3S
and blink
once
During cooling and
drying
operation, indoor unit
operates
while other loads will
stop;
during heating
operation,
the complete unit will
stop
operation.
1. Loosening or bad
contact of
indoor ambient temp.
sensor and
mainboard terminal.
2. Components in
mainboard fell
down leads short
circuit.
3. Indoor ambient
temp. sensor
damaged.(check with
sensor
resistance value
chart)
4. Mainboard
damaged.
14
Indoor
evaporator
temperature
sensor is
open/short
circuited
F2
OFF 3S
and blink
twice
AC stops operation
once reaches the
setting temperature.
Cooling, drying:
internal fan motor
stops operation while
other loads stop
operation; heating:
AC stop operation
1. Loosening or bad
contact of Indoor
evaporator temp.
sensor and
mainboard terminal.
2. Components on
the mainboard
fall down leads short
circuit.
3. Indoor evaporator
temp. sensor
damaged.(check
temp. sensor
value chart for
testing)
4. Mainboard
damaged.
15
Outdoor
ambient
temperature
sensor is
open/short
circuited
F3
OFF 3S
and blink
3 times
OFF 1S
and
blink
6 times
During cooling and
drying
operating,
compressor stops
while indoor fan
operates;
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)
