Filter
Top Products
29
Table 8 — ComfortLink™ Alarm Codes
ALARM
OR
ALERT
NUMBER
DESCRIPTION
ACTION TAKEN BY
CONTROL
RESET
METHOD
PROBABLE CAUSE
T051
Digital Compressor Control Board Alarm No action Automatic See the DSC’s LEDs for troubleshooting
Compressor A1 Safety Trip Add Strike for Circuit A Automatic
Current Sensing turned on (CS.A1 = Enable) and
should be off
Service Test --- Compressor A1 Safety Trip Add Strike for Circuit A Automatic
Current Sensing turned on (CS.A1 = Enable) and
should be off
Compressor A1 Current Detected After
Turnoff
Turn off all
compressors
Automatic
Current Sensing turned on (CS.A1 = Enable) and
should be off
Service Test --- Compressor A1 Current
Detected After Turnoff
Turn off all
compressors
Automatic
Current Sensing turned on (CS.A1 = Enable) and
should be off
T064
Circuit A Saturated Condensing Temp
Thermistor Failure
Use OAT to control
Outdoor fans
Automatic
Faulty, shorted, or open thermistor caused by wiring
error or loose connection.
T066
Circuit A Saturated Suction Temperature
Thermistor Failure
No Cooling Automatic Suction transducers internally forced inactive
T073 Outdoor Air Temperature Thermistor Failure
No cooling with
economizer
Automatic
Faulty, shorted, or open thermistor caused by wiring
error or loose connection.
T074 Space Temperature Thermistor Failure No heating or cooling Automatic
Faulty, shorted, or open thermistor caused by wiring
error or loose connection.
T075 Supply Air Temperature Thermistor Failure No cooling mode Automatic
Faulty, shorted, or open thermistor caused by wiring
error or loose connection.
T076 Return Air Thermistor Failure
No differential DB
crossover
Automatic
Faulty, shorted, or open thermistor caused by wiring
error or loose connection.
T077 Space Relative Humidity Sensor Failure
If RH.S = Yes, then no
indoor humidity control
Automatic
Faulty, shorted, or open sensor caused by wiring
error or loose connection.
T092
Circuit A Suction Pressure Transducer
Failure
Shutdown Circuit A Manual
Faulty transducer, faulty 5---V power supply, or loose
connection
T102 Compressor A1 Current Sensor Failure
If CS.A1 = Enable,
then no T051 current
alarm
Automatic
Current Sensing turned on (CS.A1 = Enable) and
should be off
T110
Circuit A Loss of Charge Shutdown Circuit A Manual Low refrigerant or faulty suction pressure transducer
Service Test --- Circuit A Loss of Charge Shutdown Circuit A Manual Low refrigerant or faulty suction pressure transducer
T126
Circuit A High Discharge Pressure Shutdown Circuit A Automatic
An overcharged system, high outdoor ambient
temperature coupled with dirty outdoor coil, plugged
filter drier, or a faulty high---pressure switch.
Service Test --- Circuit A High Discharge
Pressure
Shutdown Circuit A Automatic
An overcharged system, high outdoor ambient
temperature coupled with dirty outdoor coil, plugged
filter drier, or a faulty high---pressure switch.
T133
Circuit A Low Refrigerant Pressure Add Strike for Circuit A Automatic
Low refrigerant charge, dirty filters, evaporator fan
turning backwards, loose or broken fan belt, plugged
filter drier, faulty transducer, excessively cold return
air, or stuck open economizer when the ambient
temperature is low.
Service Test --- Circuit A Low Refrigerant
Pressure
Add Strike for Circuit A Automatic
Low refrigerant charge, dirty filters, evaporator fan
turning backwards, loose or broken fan belt, plugged
filter drier, faulty transducer, excessively cold return
air, or stuck open economizer when the ambient
temperature is low.
T143
Circuit A Failure To Pressurize Add Strike for Circuit A Automatic Wiring causing reverse rotation or faulty compressor
Service Test --- Circuit A Failure To
Pressurize
Add Strike for Circuit A Automatic Wiring causing reverse rotation or faulty compressor
T153 Real Timeclock Hardware Failure
No time and date
schedule operation
Automatic
No time/date configured, software failure, or MBB
failure
A154 Serial EEPROM Hardware Failure Unit Shutdown Automatic Software failure or MBB failure
T155 Serial EEPROM Storage Failure Error Unit operation errors Automatic Software failure or MBB failure
A156 Critical Serial EEPROM Storage Fail Error Unit Shutdown Automatic Software failure or MBB failure
A157 A/D Hardware Failure Unit Shutdown Automatic Software failure or MBB failure
A163
Circuit A Down Due to Failure Shutdown Circuit A Manual
Circuit has 3 strikes or has been locked out by
another alarm
Service Test --- Circuit ADown Due to
Failure
Shutdown Circuit A Manual
Circuit has 1 strike or has been locked out by another
alarm
* See Legend on nextpage
48/50PD