Service manual

12.2 Fault Analysis See Table 12-1
Fault Possible Cause How to Eliminate Fault Possible Cause How to Eliminate
Power failure
Resume the power
supply
4-way valve failure Replace the 4-way valve
Short circuit
Eliminate short circuit;
replace the fuse
Capillary is partially blocked Replace the capillary
Leakage between high
pressure and low pressure
section of the compressor
Replace the compressor
The pipe valve is not full open Open the valve to full
Fuse is burnt
Earth failure
(Damaged
insulation)
Eliminate the earth
failure or replace the
cable
Leakage of refrigerant
Find the leaking point and
add refrigerant
Eliminate the cause of
poor contact
The power plug is not
inserted properly or the
contact is poor
Insert into the socket
firmly
The heat insulation of
connecting pipe between
indoor unit and outdoor unit is
poor
Heat insulate the gas pipe
and liquid pipe separately
The heating load is too high
Check the predicted
heating load
Wrong cable connection
between indoor unit and
outdoor unit
Check the circuit
according to wiring
diagram and connect
correctly.
The temperature setting is too
low
Increase the temperature
setting
The controller fuse is burnt
Replace the controller
fuse
The installation position of
outdoor unit is improper
The outdoor side shall
have good ventilation and
installed with sunshade.
Neither the
indoor unit
nor the
outdoor unit
can work
The controller is burnt Replace the controller The indoor filter is blocked Clean the filter periodically.
The indoor heat exchanger is
blocked
Wash the outdoor heat
exchanger The indoor fan motor is
burnt or disconnected
Repair or replace the
fan motor
The air through indoor heat
exchanger is low
Increase the motor speed
and set it to HIGH or MED.
Compressor failure Replace the compressor
When
switched to
FAN position,
the fan does
run
Remote controller failure
Eliminate the fault or
replace the controller
4-way valve failure Replace the 4-way valve
The 1-way valve of outdoor
unit leaks
Replace the 1-way valve
Capillary is partially blocked Replace the capillary
The coil is
broken
Defrosting is not thorough
Replace the defrost temp.
sensor
The pipe valve is not full open Open the valve to full
Leakage of refrigerant
Find the leaking point and
add refrigerant
Under COOL
or HEAT
mode, neither
the indoor fan
nor the
compressor
works
Relay
failure
The contact
is poor
Replace the relay
The
heating is
poor under
HEAT
mode
operation.
The heat insulation of
connecting pipe between
indoor unit and outdoor unit is
poor
Heat insulate the gas pipe
and liquid pipe separately
Failure of outdoor fan motor Replace the motor
The indoor fan touches other
substances
Adjust the fan position
Failure of outdoor relay Replace the relay
Under COOL
or HEAT
mode, the
compressor
runs but the
outdoor fan
does not run
The defrost temp. sensor
and tube temp. sensor are
in poor contact
Replace the defrost
temp. sensor and tube
temp. sensor
The compressor vibration is
too high
Adjust the compressor
support and tighten the
loose bolts
Compressor failure
Replace the
compressor
Foreign articles inside the
indoor unit
Remove the foreign
articles
Avoid mounting on steel
window directly
Wall with appropriate
strength
Under COOL
or HEAT
mode, the
outdoor fan
runs but the
compressor
does not run
The compressor capacitor
is burnt
Replace the capacitor
The indoor unit is installed on
plate wall or thin wall thus
generating high resonance
noise
Take proper measures to
reduce the vibration.
Cooling load is too high
Check the predicted
cooling loads.
The outdoor pipes knock
each other
Separate the knocking
pipes
Temperature setting is too
high
Lower the temperature
setting
Tighten the screws
The metals inside the unit
knock each other
Add damping glue
between metal plates.
The outdoor fan knock the
casing
Adjust the fan position
Cooling unit is installed at
an improper position
The outdoor side shall
have good ventilation
and installed with
sunshade.
Abnormal noise inside the
compressor
Replace the compressor
The indoor filter is blocked
Clean the filter
periodically.
The indoor heat exchanger
is blocked
Wash the heat
exchanger
The cooling
is poor under
COOL mode
operation.
The fan speed setting is too
low
Set to HIGH or MED
speed
Abnormal
noise or
vibration
Under HEAT mode operation,
abnormal electromagnetic
noise is heard in the 4-way
valve
The electromagnetic valve
is short circuited. Replace
the electromagnetic valve.
Table 12-1
108