Service Manual
40
Installation and Maintenance
No.
Malfunction
Name
Display
Method of
Indoor Unit
A/C status
Possible Reasons
Dual-8
Code
Display
12
Outdoor
condenser
temperature
sensor is
open/short
circuited
F4
Cooling: Compressor stops
and indoor fan operates.
Heating: All the loads are
stopped.
Open-circuit or
short-circuit of outdoor
condenser temperature
sensor
13
Outdoor
discharge
temperature
sensor is
open/short
circuited
F5
Cooling: Compressor stops
and indoor fan operates.
Heating: All the loads are
stopped.
Open-circuit or
short-circuit of outdoor
discharge temperature
sensor
14
Limit/decrease
frequency due to
overload
F6
Loads are running normally.
Compressor operating
frequency is decreased.
Cooling outer tube
temperature is too high.
Heating inner tube
temperature is too high.
15
Decrease
frequency due to
overcurrent
F8
Loads are running normally.
Compressor operating
frequency is decreased.
Unit’s overall current is too
large.
16
Decrease
frequency due to
high air
discharge
F9
Loads are running normally.
Compressor operating
frequency is decreased.
Discharge temperature is
too high.
17
R o t a r y c a s i n g
stuck protection
FC
All the loads are stopped.
The rotary casing is stuck
when rotating.
18
Limit/decrease
frequency due to
antifreezing
FH
Loads are running normally.
Compressor operating
frequency is decreased.
Cooling inner tube
temperature is too low.
19
Decrease
frequency due to
high
temperature
resistant during
heating
operation
H0
Loads are running normally.
Compressor operating
frequency is decreased.
Heating inner tube
temperature is too high.
20
Defrosting
H1
A normal operation mode under heating
mode. Both
compressor and indoor fan
stop.
Too much frost on outdoor
condenser.
21
Static dedusting
protection
H2
22
Overload
protection for
compressor
H3
Cooling: Compressor stops
and indoor fan operates.
Heating: All the loads are
stopped.
Compressor temperature
is too high.
23
System is
abnormal
H4
Cooling: Compressor stops
and indoor fan operates.
Heating: All the loads are
stopped.
Outdoor tube temperature is too high under
cooling mode; Indoor tube temperature is
too high under heating mode
24
IPM protection
H5
Cooling: Compressor stops
and indoor fan operates.
Heating: All the loads are
stopped.
Compressor’s current is too
large