York IDM030B21E Series Service Manual page 46

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 THM1
(for inlet air temp.)
connected to THM1
of I.U. PCB?
Is resistance of THM1
between 0.24kΩ and
840kΩ?
Failure of I.U. PCB
Event
Failure of
Inlet Air
Thermistor
Failure of I.U. PCB
90
82
80
70
60
Thermistor
50
Resistance
(kΩ)
40
30
20
10
0
5 14
(-15) (-10) (-5) (0) (5) (10) (15) (20) (25) (30) (35) (40) (45) (50) (55) (60)
NOTE:
This figure is applicable to the following thermistors.
1. Inlet Air Thermistor (THM1), 2. Liquid Pipe Thermistor (Freeze Protection) (THM3), 3. Gas Pipe Thermistor (THM5),
4. Outlet Air Thermistor (THM2), 5. Outside Air Thermistor or Remote Thermistor (THM4)
3-24
Abnormality of Thermistor for Indoor Unit Inlet Air Temperature
1)
and the number of connected indoor units are displayed on the LCD. The indoor unit
No
Connect them.
Yes
No
Failure of
Thermistor
Yes
Cause
Failure
Incorrect Connection
61
46
35
27
20.5
16
12.5
23 32 41 50 59 68
Ambient Temperature (
(Inlet Air Thermistor)
Check Item
Check resistance.
Check connection.
Replace I.U. PCB
and check operation.
10
8
5.3
3.6
77 86 95 104 113 122 131 140
o F( o C))
Action
(Turn OFF Main Switch)
Replace thermistor
if faulty.
Correctly connect wires.
Replace I.U. PCB
if faulty.
Indication on Outdoor Unit PCB
(Alarm Code 11 ~ 19)
2.5
Unit No. of
Malfunctioning Indoor Unit
1)
,
Alarm Code
(11 ~ 19)
SM-16005-rev.2