Haier 1U71S2SG1FA Service Manual page 245

[21] Indoor Frosted
If system is lack of refrigerant
If EEV coil is connection well
If sensor terminal is
fixed well
N
If sensor resistor /
characteristic is proper
Y
If indoor air passage is
patency
Y
N
If stop valve is open
Y
Y
If ambient
temperature is too
low
N
Reconnect
N
Replace sensor
N
Modify air passage
Y
Charge refrigerant
N
Check the system piping
N
Reconnect
N
Repalce PCB
242