25
Installation and Maintenance
Service Manual
9. Maintenance
No.
Malfunction
Name
Display Method
A/C Status
Possible Causes
Dual-8
Code
Display
Indicator Display (during
blinking, ON 0.5s and OFF
0.5s)
Operation
Indicator
Cool
Indicator
Heat
Indicator
16
Outdoor
discharge
temperature
sensor is
open/short
circuited
F5
OFF 3S
and blink
5 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
17
Limit/
decrease
frequency
due to
overload
F6
OFF 3S
and blink
for 6
times
All loads operate normally,while
operation frequency for compressor is
decreased
Refer to the malfunction analysis
(overload, high temperature
resistant)
18
Decrease
frequency
due to
overcurrent
F8
OFF 3S
and blink
8 times
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
19
Decrease
frequency
due to
high air
discharge
F9
OFF 3S
and blink
9 times
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)
20
Limit/
decrease
frequency
due to
antifreezing
FH
OFF 3S
and blink
2 times
OFF 3S
and blink
2 times
All loads operate normally, while
operation frequency for compressor is
decreased
Poor air-return in indoor unit or fan
speed is too low
21
Voltage for
DC bus-bar
is too high
PH
OFF 3S
and blink
11 times
During cooling and drying operation,
compressor will stop while indoor fan
will operate;During heating operation,
the complete unit will stop operation.
1. Measure the voltage of position
L and N on wiring board (XT), if the
voltage is higher than 265VAC, turn
on the unit after the supply voltage
is increased to the normal range.
2.If the AC input isnormal, measure
the voltage of electrolytic
capacitor C on control panel (AP1),
if its normal, theres malfunction
for the circuit, please replace the
control panel (AP1)
