Carrier Error Codes

Select an error code below to identify the problem and find the solution.

Published codes

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Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.

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75 published codes

Low Stage Cool Operation

Low Stage Cool Operation. Normal low-stage cooling operation.

High Stage Cool Operation

High Stage Cool Operation. Normal high-stage cooling operation.

Brown Out Protection is Disabled

Brown Out Protection is Disabled. Brown out protection has been disabled by user selection.

Brown Out Protection is Active

Brown Out Protection is Active. Brown out protection is active.

System Communications Failure

System Communications Failure. Communication with User Interface lost.

Invalid Model Plug

Invalid Model Plug. Control does not detect a model plug or detects an invalid model plug; unit will not operate without the correct model plug.

High Pressure Switch Open

High Pressure Switch Open. High-pressure switch trip; can accumulate over multiple cycles.

Low Pressure Switch or Discharge Temp Switch Open

Low Pressure Switch or Discharge Temp Switch Open. Low-pressure switch or discharge temperature switch trip; can accumulate over multiple cycles.

Control Fault

Control Fault. Outdoor unit control board has failed and needs replacement.

Brown Out (230 V)

Brown Out (230 V). Line voltage is less than 187 V for at least 4 seconds; compressor and fan operation are not allowed until voltage exceeds 190 V.

No 230 V at Unit

No 230 V at Unit. There is no 230 V at the contactor when the indoor unit is powered and a cooling demand exists.

Outdoor Air Temp Sensor Fault

Outdoor Air Temp Sensor Fault. Outdoor air sensor not reading or out of range.

Outdoor Coil Sensor Fault

Outdoor Coil Sensor Fault. Coil sensor not reading or out of range.

Thermistors Out of Range

Thermistors Out of Range. Improper relationship between coil sensor and outdoor air sensor.

Low Stage Thermal Cutout

Low Stage Thermal Cutout. Compressor operation is detected then disappears while low-stage demand exists; can accumulate over multiple cycles.

High Stage Thermal Cutout

High Stage Thermal Cutout. Compressor operation is detected then disappears while high-stage demand exists; can accumulate over multiple cycles.

Contactor Shorted

Contactor Shorted. Compressor voltage is sensed when there is no demand for compressor operation.

No 230 V at Compressor

No 230 V at Compressor. Compressor voltage is not sensed when compressor should be starting.

Low Stage Thermal Lockout

Low Stage Thermal Lockout. Thermal cutout occurs in three consecutive low/high stage cycles; low stage locks out for 4 hours or until 24 V power is recycled.

High Stage Thermal Lockout

High Stage Thermal Lockout. Thermal cutout occurs in three consecutive high/low stage cycles; high stage locks out for 4 hours or until 24 V power is recycled.

Low Pressure Lockout

Low Pressure Lockout. Low pressure switch trip has occurred during 3 consecutive cycles; unit operation locks out for 4 hours or until 24 V power is recycled.

High Pressure Lockout

High Pressure Lockout. High pressure switch trip has occurred during 3 consecutive cycles; unit operation locks out for 4 hours or until 24 V power is recycled.

solid

Standby – No Call for Unit Operation

Standby – No Call for Unit Operation. Normal standby operation with no call for unit operation.

No Previous Code

No Previous Code. Stored status codes were erased automatically after 72 hours or manually cleared.

Blower On After Power Up

Blower On After Power Up. Blower runs for 90 seconds if the unit is powered up during a call for heat or if the heat call opens during blower on-delay.

Limit Circuit Lockout

Limit Circuit Lockout. Lockout occurs if the limit or flame rollout switch is open longer than 3 minutes or after 10 successive limit trips during high heat; auto reset after 3 hours.

Ignition Lockout

Ignition Lockout. Control will auto reset after 3 hours; refer to ignition-proving fault logic.

Blower Motor Lockout

Blower Motor Lockout. Indicates the blower failed to reach 250 RPM or failed to communicate within 30 seconds after being turned on in two successive heating cycles.

Gas Heating Lockout

Gas Heating Lockout. Control will not auto reset; check mis-wired gas valve or defective control relay.

Abnormal Flame-Proving Signal

Abnormal Flame-Proving Signal. Flame is proved while gas valve is de-energized.

Pressure Switch Did Not Open

Pressure Switch Did Not Open. Check obstructed pressure tubing or pressure switch stuck closed.

Secondary Voltage Fuse Is Open

Secondary Voltage Fuse Is Open. Check for a short circuit in secondary voltage (24 VAC) wiring.

Model Selection or Setup Error

Model Selection or Setup Error. Model plug is missing/incorrect or setup switch is positioned improperly.

High-Heat Pressure Switch or Relay Did Not Close or Reopened

High-Heat Pressure Switch or Relay Did Not Close or Reopened. High-heat pressure switch input failed to close on a call for high heat, or opened during high heat.

Low-Heat Pressure Switch Did Not Close or Reopened

Low-Heat Pressure Switch Did Not Close or Reopened. Low-heat pressure switch input failed to close on a call for low heat, or opened during low heat.

Limit Circuit Fault

Limit Circuit Fault. Limit or flame rollout is open, or furnace is operating in high-heat-only mode due to two successive low-heat limit trips.

Ignition-Proving Failure

Ignition-Proving Failure. Control will try three more times before ignition lockout 14 occurs.

Blower Motor Fault

Blower Motor Fault. Blower failed to reach 250 RPM or failed to communicate within the prescribed time limits.

Inducer Motor Fault

Inducer Motor Fault. Inducer has not started within 20 seconds after a call for heat, RPM is out of range, or RPM signal was lost for 5 seconds during operation.

Low-Heat Pressure Switch Open While High-Heat Pressure Switch Is Closed

Low-Heat Pressure Switch Open While High-Heat Pressure Switch Is Closed. Check low inlet gas pressure, plugged drain, improper pressure-switch wiring, water in vent piping, or obstructed tubing.

Control Circuitry Lockout

Control Circuitry Lockout. Auto-reset after 1 hour lockout due to flame sense circuit failure, gas valve relay stuck open, or software check error.

Compressor A1 Alert

Compressor A1 Alert. Current sensor does not detect compressor A1 current during operation, or detects current when compressor A1 should be off.

Compressor B1 Alert

Compressor B1 Alert. Current sensor does not detect compressor B1 current during operation, or detects current when compressor B1 should be off.

Compressor C1 Alert

Compressor C1 Alert. Current sensor does not detect compressor C1 current during operation, or detects current when compressor C1 should be off.

Condensing Temperature Failure - Circuit A

Condensing Temperature Failure - Circuit A. Condensing temperature is outside the valid range and fans are controlled from outdoor temperature.

Condensing Temperature Failure - Circuit B

Condensing Temperature Failure - Circuit B. Condensing temperature is outside the valid range and fans are controlled from outdoor temperature.

Outside Air Temperature Failure

Outside Air Temperature Failure. Outside-air temperature is outside the valid range; usually caused by faulty thermistor, wiring error, or loose connection.

Space Temperature Failure

Space Temperature Failure. Space temperature is outside the valid range; only occurs in Space Sensor mode.

Supply Air Temperature Failure

Supply Air Temperature Failure. Supply-air temperature is outside the valid range.

Return Air Temperature Failure

Return Air Temperature Failure. Return-air temperature is outside the valid range and RAT.S is configured as installed.

Space Relative Humidity Sensor Failure

Space Relative Humidity Sensor Failure. SPRH input is below threshold while the sensor is configured as installed.

Condensing Temperature Failure - Circuit C

Condensing Temperature Failure - Circuit C. Condensing temperature is outside the valid range and fans are controlled from outdoor temperature.

Suction Pressure Transducer Failure - Circuit A

Suction Pressure Transducer Failure - Circuit A. Suction pressure is outside the valid range and the circuit cannot run while active.

Suction Pressure Transducer Failure - Circuit B

Suction Pressure Transducer Failure - Circuit B. Suction pressure is outside the valid range and the circuit cannot run while active.

101

Suction Pressure Transducer Failure - Circuit C

Suction Pressure Transducer Failure - Circuit C. Suction pressure is outside the valid range and the circuit cannot run while active.

102

Current Sensor Failure - Compressor A1

Current Sensor Failure - Compressor A1. Current sensor output is stuck high, usually due to wiring error or loose connection.

103

Current Sensor Failure - Compressor B1

Current Sensor Failure - Compressor B1. Current sensor output is stuck high, usually due to wiring error or loose connection.

104

Current Sensor Failure - Compressor C1

Current Sensor Failure - Compressor C1. Current sensor output is stuck high, usually due to wiring error or loose connection.

Indoor Unit EEPROM Parameter Error

Indoor Unit EEPROM Parameter Error. Indoor unit EEPROM parameter error.

Indoor / Outdoor Units Communication Error

Indoor / Outdoor Units Communication Error. Communication error between indoor and outdoor units.

Zero-Crossing Signal Detection Error

Zero-Crossing Signal Detection Error. Zero-crossing signal detection error.

Indoor Fan Speed Out of Control

Indoor Fan Speed Out of Control. Indoor fan speed has been out of control.

Indoor Room Temperature Sensor T1 Open or Short

Indoor Room Temperature Sensor T1 Open or Short. Indoor room temperature sensor T1 open circuit or short circuit.

Evaporator Coil Temperature Sensor T2 Open or Short

Evaporator Coil Temperature Sensor T2 Open or Short. Evaporator coil temperature sensor T2 open circuit or short circuit.

Refrigerant Leakage Detection

Refrigerant Leakage Detection. Outdoor unit detected refrigerant leakage; function active in cooling mode.

Overload Current Protection

Overload Current Protection. Abnormal current rise detected by the specified current detection circuit.

Outdoor Ambient Temperature Sensor T4 Open or Short

Outdoor Ambient Temperature Sensor T4 Open or Short. Outdoor ambient temperature sensor T4 open circuit or short circuit.

Condenser Coil Temperature Sensor T3 Open or Short

Condenser Coil Temperature Sensor T3 Open or Short. Condenser coil temperature sensor T3 open circuit or short circuit.

Compressor Discharge Temperature Sensor T5 Open or Short

Compressor Discharge Temperature Sensor T5 Open or Short. Compressor discharge temperature sensor T5 open circuit or short circuit.

Outdoor Unit EEPROM Parameter Error

Outdoor Unit EEPROM Parameter Error. Outdoor unit EEPROM parameter error.

Outdoor Fan Speed Out of Control

Outdoor Fan Speed Out of Control. Outdoor fan speed has been out of control.

IPM Malfunction or IGBT Over-Strong Current Protection

IPM Malfunction or IGBT Over-Strong Current Protection. Voltage signal sent by the IPM to the compressor drive chip is abnormal.

Over Voltage or Over Low Voltage Protection

Over Voltage or Over Low Voltage Protection. Abnormal voltage rise or drop detected by the specified voltage detection circuit.

High Temperature Protection of Compressor Top

High Temperature Protection of Compressor Top. High temperature protection of compressor top (9k/12k models only).

Inverter Compressor Drive Error

Inverter Compressor Drive Error. Abnormal inverter compressor drive detected by special detection circuit.

14-94

Line Voltage Low

Line Voltage Low. Incoming line voltage dropped below allowed thresholds; unit will not operate or will shut down while active.

15-94

Line Voltage High

Line Voltage High. Incoming line voltage rose above allowed thresholds; unit will not operate or will shut down while active.

17-06

Lost BTM Communication

Lost BTM Communication. Lost communication with the Bluetooth module; service app will not connect while active.

18-11

Indoor Coil Freeze Protection

Indoor Coil Freeze Protection. Equipment is reducing compressor speed to prevent ice accumulation on the indoor coil.

24-58

5V PCM Power Out of Range Lockout

5V PCM Power Out of Range Lockout. PCM 5V DC supplied to VFD is interrupted or out of range, shutting the system down if not restored.

25-22

Model Plug Missing

Model Plug Missing. Model plug is not presently installed on the PCM or was not present when power was applied; equipment can still operate if a valid value is stored in memory.

25-62

Model Plug Missing Lockout

Model Plug Missing Lockout. Valid model plug was not present when power was applied and there is no valid value stored in PCM memory; equipment will not operate.

Code Index

All Codes

1 2 5 6 11 12 13 14 14-94 15 15-94 16 17-06 18-11 21 22 23 24 24-58 25 25-22 25-62 31 32 33 34 41 42 43 45 46 47 51 53 55 56 59 64 65 71 72 73 74 75 76 77 80 81 82 83 84 92 93 101 102 103 104 E0 E1 E2 E3 E4 E5 EC F0 F1 F2 F3 F4 F5 P0 P1 P2 P4 solid

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Carrier Error Codes

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Outdoor Packaged Units

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