Unclog pipe and
water pump
Is drain pan dirty and
float switch ineffective?
Is pump motor in good condition?
Is drain pipe clogged?
yes
Check if float switch is in good
condition with multimeter
Are indoor sensors for ambient
temperature and coil properly located?
Is resistance of indoor sensor correct?
Does four-way valve work properly?
Relocate
Replace four-way valve
Is outdoor four-way valve in good
condition during heating cycle?
Does small relay coil
of four-way valve have
a voltage of 12V DC?
no
Relay is broken.
Replace PCB
Is indoor unit malfunction caused by lack of refrigerant?
charge refrigerant
Is heat exchange effect adversely affected
by heavy dust in indoor and outdoor units?
cleaning
10) Temperature cutoff protection
confirm the malfunction
according to the fault code list
yes
yes
no
yes
no
yes
no
yes
no
yes
no
Replace sensor
yes
Replace indoor PCB
11) Fault in drain system
confirm the malfunction
according to the fault code list
no
yes
Replace water pump
yes
yes
Clean drain pan
no
Is float switch holder tinted that float
can't move, or too close to pump
motor that interference arises?
yes
Adjust holder
no
yes
Replace float
switch
no
Replace indoor PCB
Note: Float switch is close in normal state, when being activated, it is open. Voltage between both ends is 0V
5V when open.
when close, approximately
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Troubleshooting