Daikin R407C PLUS, Service Manual

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Si33-105 Troubleshooting
Troubleshooting R407C PLUS Series Heat Recovery System 159
3.3 Indoor Unit: Malfunction of Drain Level Control System
(33H)
Remote
Controller
Display
A3
Supposed
Causes
!
Defect of float switch or short circuit connector
!
Defect of drain pump
!
Drain clogging, upward slope, etc.
!
Defect of indoor unit PC board
!
Loose connection of connector
Troubleshooting
(VF030)
Replace float switch.
Modify the float switch's
connection and turn on again.
Connect the drain pump and
turn on again.
Check the drain piping for
clogging or upward slope, etc.
Replace indoor unit PC board.
Replace the drain pump or
check for dirt, etc.
Connect either a short circuit
connector or float switch and
turn on again.
YES
YES
YES
YES
Defect of indoor unit PC board.
Loose connection of connector.
NO NO
NO
YES
YES
NO
NO
YES
NO
YES
NO
NO
The float
switch is connected to
X18A of the indoor unit
PC board.
NO
The drain
pump works when
the power supply is reset
for the indoor unit.
The drain
pump is connected to
X25A or terminals X8S
and X9S of the indoor
unit PC board.
The voltage
of terminals X8S and
X9S or X25A is 220~240 V
(within 5minutes of
resetting the power
supply).
Water builds up
in the drain pan.
The float
switch contact is
forming a short circuit
(continuity check with X18A
disconnected)
A short
circuit connector is
connected to X18A.
Becomes
normal when X18A of
the indoor unit PC board
is short circuited
The float switch
functions normally.
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.