Trane Air Conditioners Error Codes

E0

Trane air conditioner control board display shows E0 and system will not start cooling or heating.

Communication Fault Between Indoor and Outdoor Unit

E1

Trane air conditioner displays E1 and shuts down or will not start; may attempt to start and then stop quickly.

High-Pressure Protection Trip

E2

Trane air conditioner shows E2 and may run briefly then shut down; poor cooling performance.

Low-Pressure Protection / Low Refrigerant or Restricted Flow

E3

Trane air conditioner displays E3 and outdoor unit does not start or cycles off quickly.

Outdoor Fan Motor Fault / Fan Feedback Error

E4

Trane air conditioner shows E4 and shuts down; may be accompanied by ice on the indoor coil or very low airflow.

Evaporator Coil Freeze Protection / Low Airflow

E5

Trane air conditioner displays E5 and will not run or stops shortly after starting.

Overcurrent Protection / Compressor Overload

E6

Trane air conditioner shows E6 and may not respond to thermostat commands; indoor and outdoor units may not coordinate.

Indoor-Outdoor Communication Error / Data Link Failure

E7

Trane air conditioner displays E7 and the outdoor unit does not start; thermostat may show a communication or outdoor unit error.

Outdoor Unit Offline / No Feedback

E8

Trane air conditioner shows E8 and may shut down due to abnormal discharge temperature or compressor protection.

Discharge Temperature High / Compressor Overheat

E9

Trane air conditioner displays E9 and may not maintain set temperature; system may short-cycle.

Indoor Temperature Sensor Fault / Thermistor Error

F0

Trane air conditioner control shows F0 and system may not start or may run erratically.

EEPROM / Control Board Memory Error

F1

Trane air conditioner shows F1 and may not respond correctly to thermostat settings; temperature swings are noticeable.

Room Temperature Sensor Out of Range

F2

Trane air conditioner displays F2 and may shut down or limit operation; coil temperature readings appear abnormal.

Evaporator Coil Temperature Sensor Fault

F3

Trane air conditioner shows F3 and may stop cooling; outdoor unit may shut down on protection.

Outdoor Ambient Temperature Sensor Fault

F4

Trane air conditioner displays F4 and may limit compressor operation; defrost or protection modes may be affected on heat pump models.

Condenser Coil Temperature Sensor Fault

F5

Trane air conditioner shows F5 and may not start the compressor; system may run fan only.

Compressor Temperature Sensor Fault

F6

Trane air conditioner displays F6 and may not modulate capacity correctly on variable-speed or inverter models.

Compressor Current Sensor / Inverter Protection Fault

F7

Trane air conditioner shows F7 and may not start; fan may run but compressor stays off.

Phase Loss / Phase Reversal (Three-Phase Units)

F8

Trane air conditioner displays F8 and may shut down due to abnormal fan speed or feedback.

Indoor Fan Motor Feedback Fault (ECM/Variable-Speed)

F9

Trane air conditioner shows F9 and may not operate correctly in defrost or low ambient conditions (heat pump models).

Defrost Sensor / Defrost Control Fault

Symptom

Burning or electrical smell from the Trane indoor or outdoor unit during operation.

Overheating Electrical Component

Symptom

High-pitched squealing or screeching noise from the indoor Trane air handler or furnace when AC is running.

Blower Motor or Belt Noise

Symptom

Ice forming on the Trane outdoor unit refrigerant lines or on the indoor evaporator coil.

System Icing / Low Suction Pressure

Symptom

Musty or moldy odor from vents when the Trane air conditioner starts.

Biological Growth on Evaporator Coil or in Ducts

Symptom

Outdoor Trane air conditioner unit will not start at all; no fan, no compressor, thermostat appears normal.

No Power to Outdoor Condenser

Symptom

Trane air conditioner causes noticeable vibration and rattling noises in the outdoor unit or connected ductwork.

Excessive Vibration / Mounting Issues

Symptom

Trane air conditioner does not respond to thermostat changes; system stays off or stuck in one mode.

Control Logic / Thermostat Communication Issue

Symptom

Trane air conditioner indoor blower runs but airflow from vents is weak.

Insufficient Indoor Airflow

Symptom

Trane air conditioner indoor blower runs but outdoor unit does not; warm air blows from vents.

Outdoor Unit Not Responding to Cooling Call

Symptom

Trane air conditioner indoor unit is very noisy with a rattling or buzzing sound when the blower runs.

Loose Components in Air Handler

Symptom

Trane air conditioner outdoor fan runs but compressor does not; no cooling is produced.

Compressor Not Starting

Symptom

Trane air conditioner produces a loud banging or clanking noise from the outdoor unit during operation.

Mechanical Noise from Fan or Compressor

Symptom

Trane air conditioner runs but does not cool well; supply air is only slightly cooler than room temperature.

Poor Cooling Performance / Underperformance

Symptom

Trane air conditioner runs continuously and does not shut off even when the set temperature is reached.

Stuck Cooling Call / Control Staging Fault

Symptom

Trane air conditioner short cycles, turning on and off frequently without reaching set temperature.

Short Cycling / Improper System Control

Symptom

Trane air conditioner trips the breaker immediately or shortly after starting.

High Inrush or Short Circuit

Symptom

Trane air conditioner will not start; thermostat is blank or unresponsive.

No Thermostat Power / Control Circuit Failure

Symptom

Trane outdoor unit makes a loud humming sound but the fan and compressor do not start.

Failed Start/Run Capacitor

Symptom

Water dripping from the Trane outdoor unit base or excessive water around the pad.

Normal Condensation vs. Abnormal Outdoor Coil Frost Melt

Symptom

Water leaking from around the indoor Trane air handler or furnace during cooling operation.

Condensate Drain Clog / Drain Pan Overflow