Hisense AHM-080HCDSAA - Page 329

308
Troubleshooting
Phenomenon Cause Check item
Action
(Turn OFF the main switch)
Insu󰀩cient heating
process
Indoor heat load is greater than the heating
capacity
Calculate the heat load
Replace the unit with a bigger
unit
Excessively low
suction pressure
Gas leakage or insu󰀩cient
refrigerant charge
Measure superheat
Correctly charge the refrigerant
after the gas leakage check and
repairing
Excessively small diameter
or long piping
Measure the eld supplied
piping
Use the specied pipes
Failure or malfunction of
the expansion valve
Check for clogging Remove the clogging
Check the connection cord and
the connector
Replace the connector
Is there an operation sound from
the coil?
Replace the coil
Is the thermistor on the
compressor normal?
Replace the thermistor
Is the thermistor installed
correctly on compressor?
Correctly install the thermistor
Clogging of O.U. strainer
Check the temperature
di󰀨erence between the inlet and
the outlet of strainer
Replace the strainer for the
outdoor unit
Clogging of suction piping
Check the temperature
di󰀨erence of each part
Remove the clogging
Insu󰀩cient air ow through
the outdoor unit heat
exchanger
Is the outdoor unit heat
exchanger clogged?
Remove the clogging
Are there any obstacles at the
inlet or the outlet of outdoor
unit?
Remove the obstacles
Is the service area for the
outdoor unit su󰀩cient?
Secure a su󰀩cient service
area
Check the speed of the outdoor
unit fan
Replace the fan motor
Excessively low air
temperature through
the outdoor unit heat
exchanger
Check for any short-circuited air
to the outdoor unit
Remove the cause of the short-
circuited air
Defrosting is insu󰀩ciently
completed
Check the thermistor for the
defrost operation
Replace the thermistor for the
defrost operation
Excessively high
discharge pressure
Excessively charged
refrigerant
Check the refrigerant quantity Correctly charge the refrigerant
Non-condensate gas in
refrigerant cycle
Check the refrigerant quantity
Recharge the refrigerant after
the vacuum pumping
Clogging of the discharge
pressure piping
Check for clogging Remove the clogging
Malfunction or internal leakage of the 4-way
reversing valve
Check the temperature
di󰀨erence at the inlet and the
outlet of the 4-way reversing
valve
Replace the 4-way reversing
valve
Malfunction of the check valve of the outdoor
unit
Check the temperature
di󰀨erence at the inlet and the
outlet of the check valve
Replace the check valve
Excessively high
suction pressure
Malfunction or internal
leakage of 4-way reversing
valve
Check the temperature
di󰀨erence at the inlet and the
outlet of the 4-way reversing
valve
Replace the 4-way reversing
valve
Discharge temperature of the indoor unit is
unstable
Check the expansion valve of
the outdoor unit
Replace the failed expansion
valve of the outdoor unit