LG ATNH09GRLE2 Svc Manual page 69

4. Trouble Shooting
6.6 Troubleshooting Indoor Error
CH 04 (Drain pump error)
Is the drain pan filled
half with condensate
water? (half level of
float switch)*
Yes
Is drain pump working?
(Sound/drain noise/
contact etc.)
Yes
Drain pump blocked by
foreign particles?
Yes
Remove it & clean the pump
* If the float goes up higher than a half of float
switch then the circuit is open & the unit is
stopped automatically.
float
Condensate water
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Only for training and service purposes
Is Float switch short
No
On measuring its
resistance?
Yes
Replace Indoor PCB or
reconnect the connector
In indoor unit PCB
No
Does the terminal voltage
for drain pump has
220V output?**
Yes
Replace Drain Pump
No
Check the drain head height
and slope***
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No
Replace float switch
No
Replace indoor unit PCB
Checking float
switch
(Low position short 0 ohm )
(High position Open)
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