Service Manual

SiUS071735E Troubleshooting
Service Diagnosis 64
4.3 Drain Level Control System Abnormality
Error Code A3
Method of Error
Detection
The float switch detects error.
Error Decision
Conditions
The water level reaches its upper limit and the float switch turns OFF.
Supposed
Causes
 Defective drain pump
 Improper drain piping work
 Clogged drain piping
 Defective float switch
 Defective indoor unit PCB
 Defective connector X15A, X25A on indoor unit PCB
Troubleshooting
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Connect the drain pump.
Replace the indoor unit
PCB (control PCB).
Replace the drain pump.
There is a drain system
abnormality.
Connect the float switch.
Replace the float switch.
Replace the indoor unit
PCB (control PCB).
(R25079)
NO
YES
NO
NO
YES
YES
Is the drain
pump connected to X25A
on the indoor unit
PCB?
NO
Is the drain water level
abnormally high?
YES
YES
Is the float switch
connected to X15A?
NO
Does the
drain pump work after
the power supply is
on?
Is the
voltage of connector X25A
13 VDC?
YES
Remove the float switch from
X15A, short circuit X15A, and
restart operation.
NO
Does A3
appear on the remote
controller display?