York CIDH018B21S, Service Manual

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3-28
SM-18001-rev.1
TROUBLESHOOTING
Alarm
Code
Abnormality of Thermistor for Liquid Refrigerant Pipe Temperature
at Indoor Unit Heat Exchanger (Freeze Protection Thermistor)
l
The RUN indicator (red) flashes.
l
The indoor unit number (refrigerant cycle number - address number), the alarm code, the model code
1
,
the model name
1
and the number of connected indoor units are displayed on the LCD. The indoor unit
number and the alarm code are displayed on the 7-segment display of the outdoor unit PCB.
Note 1: Except for some models.
This alarm code is displayed when a short (0.24kΩ or less) or open sensor (840kΩ or more) is detected
during a heating or cooling operation. The operation automatically restarts when the malfunction is
removed.
Cause Check Item
Action
(Turn OFF Main Switch)
Event
Failure of
Freeze Protection
Thermistor
Check resistance.
Replace thermistor
if faulty.
Failure
Check wiring to
I.U. PCB.
Correctly connect wires.
Incorrect Connection
Replace I.U. PCB
and check operation.
Replace I.U. PCB
if faulty.
Failure of I.U. PCB
● High Static Type: (H,Y)IDH018 to 048B21S
● Medium Static Type: (H,Y,C)IDM006 to 048B21S ● Slim Type: (H,Y,C)IDS006 to 018B21S
Thermistor for Indoor Heat
Exchanger Liquid Pipe
Temperature
(For Freeze Protection)
Thermistor for Indoor Heat
Exchanger Liquid Pipe
Temperature
(For Freeze Protection)
Thermistor for Indoor Heat
Exchanger Liquid Pipe
Temperature
(For Freeze Protection)
Yes
Connect them.
No
Refer to "Alarm Code 11"
for thermistor resistance.
Is thermistor THM3
(for freeze protection)
connected to THM3 of
I.U. PCB?
Yes
No
Is resistance of THM3
between 0.24k Ω and
840k Ω ?
Failure of I.U. PCB
Failure of
Thermistor