Haier AW07EH2VHA, Service Manual

Page: 136 / 140

TROUBLESHOOTING & REFERENCES
J-24
ENGLISH
Topic Title Flow Charts
[16] Lack of refrigerant or discharging pipe blocked
Discharge & suction temperature Td-Ts≥80°C 10 minutes
after compressor start. Error status locks if it occurs 3 times
in 1 hour.
Possible causes:
• Wrong sensor connection
• Lack of refrigerant
• The senor is bad
• The 4-way valve is bad
• The electronic expansion valve is bad
• Out of the operating range
Correct wiring
Is the sensor wiring correct
and firmly connected?
Is the system leaking, or
lacking refrigerant?
Is the resistance of the
Td and the Tcm sensors
within range?
Repair leak and recharge
refrigerant
Replace the
sensor
Yes
No
Yes
No
Use the unit according to
the allowable operating
range of the unit.
Yes
Is there an Internal
leakage in the 4-way
valve?
No
Replace 4-way
valve
Yes
No
Adjust the valve opening
Yes
Is the electronic
expansion valve over
throttled?
[17] 4-way valve reversing failure
Indoor pipe & indoor ambient temperature Tm-Tai≥5°C
10 minutes after compressor started. Error status locks
if it occurs 3 times in 1 hour.
Possible causes:
• The 4-way valve is bad
• The PCB is bad
• The 4-way valve coil connection is bad
•
The system pressure difference is too small.
Reconnect
Is connection between the
4-way valve and PCB is good?
Is the 4-way valve coil
wiring firmly in place and
characteristics correct?
Is the system meeting
4-way valve reversing
conditions (Pd-
Ps>0.6Mpa)?
Is there air noise after 4-way
valve reverses, and the temp.
of connection pipes on 4-way
valve normal?
Correct wiring or replace
Check if the
compressor is running
Replace
PCB
Replace 4-way
valve
Yes
Yes
Yes
No
Yes
No
No
Yes
No
Is 208/230VAC Measured on
PVB CN5 PCB after 4-way
valve reversing conditons are
met?