York IDM030B21E Series Service Manual page 48

TROUBLESHOOTING
Alarm
Code
l The RUN indicator (red) flashes.
l The indoor unit number (refrigerant cycle number - address number), the alarm code, the model code*
the model name*
number and the alarm code are displayed on the 7-segment display of the outdoor unit PCB.
*1) Except for some models.
H This alarm code is displayed when a short circuit (0.24kΩ or less) or disconnection (840kΩ or more) of
the thermistor is detected during a heating or cooling operation. The operation automatically restarts
when the malfunction is removed.
Is thermistor THM3
(for freeze protection)
connected to THM3 of
I.U. PCB?
Is resistance of THM3
between 0.24kΩ and
840kΩ?
Failure of I.U. PCB
Event
Failure of
Freeze Protection
Thermistor
Failure of I.U. PCB
3-26
Abnormality of Thermistor for Liquid Refrigerant Pipe Temperature
at Indoor Unit Heat Exchanger (Freeze Protection Thermistor)
1)
and the number of connected indoor units are displayed on the LCD. The indoor unit
No
Connect them.
Yes
No
Refer to "Alarm Code 11"
Yes
for thermistor resistance.
Cause
Failure
Incorrect Connection
Failure of
Thermistor
Check Item
Check resistance.
Check wiring to
I.U. PCB.
Replace I.U. PCB
and check operation.
1)
,
Action
(Turn OFF Main Switch)
Replace thermistor
if faulty.
Correctly connect wires.
Replace I.U. PCB
if faulty.
SM-16005-rev.2