Error No.
Error Type
Error Point
Main Reasons
04
Drain pump error
Float switch is open due to 
rising of condensate water 
level because of drain 
pump fault or drain pipe 
clogging
1. Drain pump/float switch fault
2. Improper drain pipe location, clogging  
 
of drain pipe
3. Indoor unit PCB fault
■ Error diagnosis and countermeasure flow chart
Is the drain pan filled 
half with condensate 
water? (half level of 
float switch)*
Is drain pump working?
(Sound/drain noise/
contact etc.)
Replace float switch
Replace Indoor PCB or 
reconnect the connector
Yes 
Yes 
No 
No 
Is Float switch short 
On measuring its 
resistance?  
No 
Yes 
Drain pump blocked by
foreign particles?
Yes 
No 
In indoor unit PCB 
Does the terminal voltage 
for drain pump has 
DC 15V output?
Replace indoor unit PCB
Replace Drain Pump
Yes 
Check the drain head height 
and slope***
Remove it & clean the pump
float
Checking float switch
No 
 (Low position 
 short   0 ohm )
* If the float goes up higher than a half of float
switch then the circuit is open & the unit is
stopped automatically.
(High position     Open)
Condensate water