York CIDH018B21S, Service Manual

Page: 47 / 186

SM-18001-rev.1
3-25
TROUBLESHOOTING
Alarm
Code
Abnormality of Thermistor for Indoor Unit Inlet Air Temperature
(Inlet Air 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
Inlet Air
Thermistor
Check resistance.
Replace thermistor
if faulty.
Failure
Check connection.
Correctly connect wires.
Incorrect Connection
Replace I.U. PCB
and check operation.
Replace I.U. PCB
if faulty.
Failure of I.U. PCB
Thermistor for
Air Inlet Temperature
● High Static Type: (H,Y)IDH018 - 048B21S
● Medium Static Type: (H,Y,C)IDM006 - 048B21S ● Slim Type: (H,Y,C)IDS006 - 018B21S
Thermistor for
Air Inlet Temperature
Thermistor for
Air Inlet Temperature
Yes
Yes
Connect them.
No
Failure of
Thermistor
Failure of I.U. PCB
No
Is thermistor THM1
(for inlet air temp.)
connected to THM1
of I.U. PCB?
Is resistance of THM1
between 0.24k Ω and
840k Ω ?