York IDM030B21E Series Service Manual page 50

TROUBLESHOOTING
Alarm
Code
l The RUN indicator (red) flashes.
l The indoor unit number and the alarm code are displayed on the LCD. The alarm code is displayed on
the 7-segment display of the outdoor unit PCB.
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.
Is resistance of THM4
(for Outside Air Temperature)
between 0.24kΩ and 840kΩ?
Failure of I.U. PCB
Event
Failure of
Failure of
Thermistor for
Outlet Air
Outside Air
Thermistor
Temperature
Failure of I.U. PCB
3-28
Abnormality of Thermistor for Outside Air Temperature
(for Ducted (Medium Static) with EconoFresh Kit)
No
Failure of
Thermistor
Refer to "Alarm Code 11"
Yes
for thermistor resistance.
Cause
Failure
Incorrect Connection
Check Item
Check resistance.
Check wiring to
I.U. PCB.
Replace I.U. PCB
and check operation.
Action
(Turn OFF Main Switch)
Replace thermistor
if faulty.
Correctly connect wires.
Replace I.U. PCB
if faulty.
SM-16005-rev.2