Haier AW07EH2VHA, Service Manual

Page: 139 / 140

TROUBLESHOOTING & REFERENCES
J-27
ENGLISH
Topic Title Flow Charts
Reconnect
Power off. Is pressure switch
wiring connection ok?
Use multimeter to check the high
pressure switch. Is the switch
short circuited?
Is the EEV coil wiring correct and
firmly in place?
Is the stop valve is open?
Use a multimeter to check
the resistance of Tc & Tm.
Are they withing range?
Is the piping system is
clogged?
Is the connection pipe is bent?
The pressure is bad,
replace it.
Open the stop valve
Clean the piping system
Replace the connection
pipe
Replace the
sensor
Yes
Yes
No
Yes
Yes
No
No
No
No
No
Yes
No
No
Reconnect the EEV
coil wiring
[44] High pressure detected in system
The minimum temperature value of indoor pipe Tm
and outdoor Ts is lower than -45 °C during cooling
mode, or minimum temperature value of outdoor Tc
and outdoor Te is lower than -45 °C.
Possible causes:
• High pressure sensor detection value is incorrect
• Refrigerant overcharge
• Blocked liquid line piping
• The outdoor unit cannot be turned on normally
due to failure to open outdoor heat exchanger
electronic expansion valve when heating.
• The operation environment is beyond the allowed
range.
Power on
Short the low pressure
switch terminal on the PCB.
Does the system report a
failure?
Is the fan motor ok?
Is the resistance of Te and
Tc2 in range?
The PCB is bad,
replace it.
Replace
sensor
No
Yes
Yes
Yes
No
No
Replace the fan
motor
[45] Low pressure detected in system
The minimum temperature value of indoor pipe Tm and
outdoor Ts is lower than -45 °C during cooling mode, or
minimum temperature value of outdoor Tc and outdoor Te is
lower than -45 °C.
Possible causes:
• Low pressure sensor detection value is incorrect
• Low refrigerant charge
• System air leakage
• Blocked low pressure or liquid line piping
• The outdoor unit cannot be turned on normally due to failure
to open outdoor heat exchanger electronic expansion valve
when heating.
• The operation environment is beyond the allowed range.