Hisense AHM-080HCDSAA - Abnormal Operation of the Devices

306
Troubleshooting
1.1.5 Abnormal operation of the devices
Phenomenon Cause Check item
Action
(Turn OFF the main switch)
No defrost operation
mode is available
during the heating
process or the
defrost operation
continues
Failure of thermistor
for outdoor
evaporating
temperature (Te)
and Te2 during
heating
Failure of thermistor
Replace or correctly connect when it is abnormal
Disconnected wire of
thermistor or wrong
installation position for Te
and Te2.
Failure of 4-way
reversing valve
Disconnected 4-way
reversing valve coil
Measure the resistance of coil
Replace the 4-way reversing
valve
Incorrect activation of
4-way reversing valve
Enforced power supply
Disconnected control wires between indoor unit
and outdoor unit
Check the connectors Correctly connect the wiring
Failure of the PCB
of the indoor unit
Disconnected wiring to
PCB
Check the connectors Correctly connect the wiring
Failure of PCB
Check PCB by means of the self-
check mode
Replace PCB when the check
mode is not available
Failure of the PCB
of the indoor unit
Disconnected wiring to
PCB
Check the connectors Correctly connect the wiring
Failure of the PCB
Check PCB by means of the self-
check mode
Replace if PCB fails
Insu󰀩cient cooling
process
Indoor cool load is higher than the cooling
capacity
Calculate the cool load Use a bigger unit
Excessively low
suction pressure
Gas leakage or shortage
of refrigerant
Measure superheat
Correctly charge the refrigerant
after repairing the gas leakage
Excessively small
diameter tube or long
piping
Measure and check the eld-
supplied pipes
Use the correct pipes
Incorrect activation of
the check valve of the
outdoor unit
Check whether or not the
temperature di󰀨erence before/
after the check valve
Replace the check valve of the
outdoor unit
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
Clogged strainer in the
outdoor unit; clogging at
the low pressure piping
Check the temperature di󰀨erence
at the inlet and the outlet of the
strainer
Replace the strainer in the
outdoor unit
Clogging at the low
pressure piping
Check the temperature di󰀨erence Remove the clogging