Error-code hub

Carrier error codes

Carrier ductless systems show a code on the indoor unit or wired controller, and the 31 codes below cover the Comfort, Performance and Infinity ranges. Note that Carrier's own ductless line is distinct from Toshiba Carrier, the joint-venture brand, which uses a different diagnostic scheme and has separate pages here.

See Carriermini-splits ->Common First Status Displays Error Codes

Status displays: 2
Error codes: 31

Unit applicability

Match your unit before reading the table

This table is sourced for Comfort 22. If your unit is a different generation or product line not named here, the same display code may vary by generation.

Comfort 228 models

Common codes first

Most broadly applicable documented codes

Ranking basis: we do not have failure-frequency telemetry. These are ordered by breadth of affected systems in the SplitAtlas catalog - the documented product line's published model count, whether the same code appears on more than one product line, and any manual applicability notes we hold. This is a breadth ranking, not a popularity claim.

EC0D

EC0D is a broad outdoor-unit malfunction display. It means the outdoor unit needs diagnosis, but the homeowner display does not identify one single failed part.

AdvisoryTechnician

Breadth evidence: 8 published catalog models on its documented product line.
Safe first check: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.

View the fix

EC07

EC07 means the outdoor unit is not seeing outdoor fan speed the way it expects. The system may stop or limit operation to protect the outdoor unit.

AdvisoryTechnician

Breadth evidence: 8 published catalog models on its documented product line.
Safe first check: Turn the system off. From outside the cabinet only, make sure leaves, snow, or stored items are not blocking the outdoor unit. Then use one safe power reset; if EC07 returns, call for service.

View the fix

EC51

EC51 means the outdoor control has an EEPROM parameter error. In plain terms, the outdoor board is not accepting stored configuration data correctly.

AdvisoryTechnician

Breadth evidence: 8 published catalog models on its documented product line.
Safe first check: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.

View the fix

EC52

EC52 means the outdoor unit is not getting a valid outdoor coil temperature reading. The system needs that reading to control heating, cooling, and defrost.

AdvisoryTechnician

Breadth evidence: 8 published catalog models on its documented product line.
Safe first check: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.

View the fix

EC53

EC53 means the outdoor unit is not getting a valid outdoor air temperature reading. That reading affects capacity control and cold-weather operation.

AdvisoryTechnician

Breadth evidence: 8 published catalog models on its documented product line.
Safe first check: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.

View the fix

EC54

EC54 means the outdoor unit is not getting a valid compressor discharge-temperature reading. Because discharge temperature protects the compressor and refrigerant circuit, this is a pro-only fault.

AdvisoryTechnician

Breadth evidence: 8 published catalog models on its documented product line.
Safe first check: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.

View the fix

Safe first checks

Checks you can do without opening the unit

These codes have homeowner-safe steps such as filters, airflow, condensate/drain checks, remote/controller items, or a single safe power reset. If the code returns, stop at the boundary in the card.

EC0DTechnician

Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.

Read the full code guide

EC07Technician

Turn the system off. From outside the cabinet only, make sure leaves, snow, or stored items are not blocking the outdoor unit. Then use one safe power reset; if EC07 returns, call for service.

Read the full code guide

EC51Technician

Read the full code guide

EC52Technician

Read the full code guide

Carrier mini-splits

Use the Carrier catalog to connect these manual error codes to current model pages and replacement options.

See Carriermini-splits ->

Status displays

DF

DF means the heat pump is melting frost from the outdoor unit during heating. Carrier's manual says DF in defrost mode is not an error code.

Not an error

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Let the defrost cycle finish. Steam, water, and a short pause in warm indoor airflow can be normal during defrost.
Status note: Carrier identifies this as a normal display, not an error code.

View the fix ->

FC

FC means forced cooling mode is active. Carrier's manual says FC in forced cooling mode is not an error code.

Not an error

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: If a technician placed the unit in forced cooling, let them finish. If FC appears during normal use and will not clear, turn the system off once and schedule service.
Status note: Carrier identifies this as a normal display, not an error code.

View the fix ->

All error codes

EC07

EC07 means the outdoor unit is not seeing outdoor fan speed the way it expects. The system may stop or limit operation to protect the outdoor unit.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off. From outside the cabinet only, make sure leaves, snow, or stored items are not blocking the outdoor unit. Then use one safe power reset; if EC07 returns, call for service.
When to call a pro: Call a licensed HVAC technician if EC07 returns or the outdoor fan is not running normally. Tell them Carrier lists EC07 as outdoor fan speed out of control.

View the fix ->

EC0D

EC0D is a broad outdoor-unit malfunction display. It means the outdoor unit needs diagnosis, but the homeowner display does not identify one single failed part.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EC0D returns after one reset. Tell them Carrier lists EC0d as ODU malfunction.

View the fix ->

EC51

EC51 means the outdoor control has an EEPROM parameter error. In plain terms, the outdoor board is not accepting stored configuration data correctly.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EC51 returns after one reset. Tell them Carrier identifies it as an outdoor EEPROM parameter error.

View the fix ->

EC52

EC52 means the outdoor unit is not getting a valid outdoor coil temperature reading. The system needs that reading to control heating, cooling, and defrost.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EC52 returns. Tell them Carrier identifies EC52 as the outdoor coil temperature sensor error.

View the fix ->

EC53

EC53 means the outdoor unit is not getting a valid outdoor air temperature reading. That reading affects capacity control and cold-weather operation.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EC53 returns. Tell them Carrier identifies EC53 as the outdoor ambient temperature sensor error.

View the fix ->

EC54

EC54 means the outdoor unit is not getting a valid compressor discharge-temperature reading. Because discharge temperature protects the compressor and refrigerant circuit, this is a pro-only fault.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EC54 returns. Tell them Carrier identifies EC54 as the compressor discharge temperature sensor error.

View the fix ->

EC56

EC56 means the indoor coil outlet temperature reading is not valid. The system may stop because it cannot safely confirm coil conditions.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EC56 returns. Tell them Carrier identifies EC56 as the indoor coil outlet temperature sensor error.

View the fix ->

EH00

EH00 means the indoor control has an EEPROM malfunction. The indoor board is not reading stored control data correctly.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EH00 returns after one reset. Tell them Carrier identifies EH00 as indoor EEPROM malfunction.

View the fix ->

EH03

EH03 means the indoor unit is not seeing indoor fan speed the way it expects. The system may stop to protect the indoor coil and motor circuit.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off, clean the user-removable filter, and make sure curtains or furniture are not blocking the indoor air inlet/outlet. Power reset once if safe; if EH03 returns, call for service.
When to call a pro: Call a licensed HVAC technician if EH03 returns after the filter and airflow checks. Tell them Carrier lists EH03 as indoor fan speed out of control.

View the fix ->

EH0A

EH0A means the indoor control is not accepting stored configuration data correctly.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EH0A returns after one reset. Tell them Carrier identifies EH0A as an indoor EEPROM parameter error.

View the fix ->

EH0B

EH0B means the indoor main control board and indoor display board are not exchanging the expected signal. The remote may still light up, but the unit controls cannot coordinate correctly.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EH0B returns. Tell them Carrier identifies EH0b as communication between the indoor main control and display boards.

View the fix ->

EH0E

EH0E means the indoor unit is reporting a water-level alarm malfunction. Treat it seriously because condensate faults can lead to water damage.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off if water is visible. Check only the outside end of the drain for an obvious blockage or kink, then power reset once if everything is dry and safe. Do not open the indoor unit.
When to call a pro: Call a licensed HVAC technician if EH0E returns, water is visible, or the drain path is not obvious. Tell them Carrier lists EH0E as water-level alarm malfunction.

View the fix ->

EH3A

EH3A means the external fan module is seeing DC bus voltage below its expected range. This is an electrical protection fault.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician or electrician if EH3A returns. Tell them Carrier identifies EH3A as external fan DC bus voltage too low protection.

View the fix ->

EH3B

EH3B means the external fan module is seeing DC bus voltage above its expected range. This is an electrical protection fault.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician or electrician if EH3B returns. Tell them Carrier identifies EH3b as external fan DC bus voltage too high fault.

View the fix ->

EH60

EH60 means the indoor unit is not getting a valid room-temperature reading. The unit may not know the actual room temperature.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EH60 returns. Tell them Carrier identifies EH60 as indoor room temperature sensor T1 error.

View the fix ->

EH61

EH61 means the indoor unit is not getting a valid indoor coil temperature reading. That reading protects the coil and supports heating/cooling control.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EH61 returns. Tell them Carrier identifies EH61 as indoor coil temperature sensor T2 error.

View the fix ->

EH62

EH62 means the T2B evaporator coil inlet temperature sensor circuit is open or shorted. The indoor unit cannot rely on that temperature reading.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EH62 returns. Tell them Carrier groups EH62/EH66 with the evaporator coil inlet temperature sensor T2B open/short fault.

View the fix ->

EH65

EH65 means the T2A evaporator coil inlet temperature sensor circuit is open or shorted. The indoor unit cannot rely on that temperature reading.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EH65 returns. Tell them Carrier identifies EH65 as evaporator coil inlet temperature sensor T2A open/short fault.

View the fix ->

EH66

EH66 means the T2B evaporator coil inlet temperature sensor circuit is open or shorted. Carrier lists it on the same row as EH62.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EH66 returns. Tell them Carrier groups EH62/EH66 with the evaporator coil inlet temperature sensor T2B open/short fault.

View the fix ->

EHB3

EHB3 means the wired controller and master control are not communicating correctly. The control may not be able to command the indoor unit reliably.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EHB3 returns or a wired wall controller is installed. Tell them Carrier identifies EHb3 as communication between wire and master control.

View the fix ->

EHBA

EHBA means the indoor control is not communicating with the external fan module. This is a control/wiring diagnosis, not a remote-control setting.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EHBA returns. Tell them Carrier identifies EHbA as communication between the indoor unit and external fan module.

View the fix ->

EL01

EL01 means the indoor unit and outdoor unit are not exchanging the expected control signal, so the heat pump cannot coordinate operation reliably.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EL01 returns after one safe reset or appeared after installation/service. Tell them Carrier identifies EL01 as indoor/outdoor communication error.

View the fix ->

EL0C

EL0C means the system is reporting a lack of refrigerant. Because this R-454B equipment uses flammable refrigerant, do not try to add refrigerant, attach gauges, or keep restarting it.

Stop useTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Stop normal heating/cooling use. Ventilate if you suspect a leak, keep flames and ignition sources away, and do not attach gauges or open covers. Call a pro.
When to call a pro: Call a licensed HVAC technician trained for R-454B/A2L refrigerant. Tell them Carrier identifies EL0C as system lacks refrigerant.

View the fix ->

EL16

EL16 means the adapter board and outdoor main board are not exchanging the expected signal. This is a board/wiring fault that needs service.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if EL16 returns. Tell them Carrier identifies EL16 as communication between the adapter board and outdoor main board.

View the fix ->

FL09

FL09 means Carrier's control is seeing a platform mismatch. This usually points to equipment, board, or configuration mismatch after installation or service.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call the installer or a licensed HVAC technician if FL09 appears. Tell them Carrier identifies FL09 as a new/old platform mismatch.

View the fix ->

PC00

PC00 means the outdoor inverter power module protection has operated. That module drives the compressor, so this is not a homeowner repair.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if PC00 returns after one safe reset. Tell them Carrier identifies PC00 as outdoor IPM module protection.

View the fix ->

PC01

PC01 means the outdoor unit detected voltage outside the expected range. The system may stop to protect the inverter and compressor electronics.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Power cycle once at the breaker if you can do that safely. If PC01 returns, the breaker trips, or lights in the home dim or flicker, stop and call for service.
When to call a pro: Call a licensed HVAC technician or electrician if PC01 returns, the breaker trips, or other lights/appliances show voltage symptoms.

View the fix ->

PC02

PC02 means the compressor top or inverter module temperature protection has operated. The unit is protecting expensive outdoor electronics and the compressor.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off. Clean the indoor filter and make sure indoor and outdoor air paths are not blocked. Power reset once if safe; if PC02 returns, call for service.
When to call a pro: Call a licensed HVAC technician if PC02 returns after the airflow checks and one reset. Tell them Carrier identifies PC02 as compressor top/IPM temperature protection.

View the fix ->

PC03

PC03 means the outdoor unit has detected low- or high-pressure protection. Pressure faults involve the refrigerant circuit and require professional diagnosis.

Stop useTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off. Clear only obvious outdoor obstructions and clean the indoor filter. Do not connect gauges or keep resetting; call a pro if PC03 returns.
When to call a pro: Call a licensed HVAC technician if PC03 returns. Tell them Carrier identifies PC03 as low- or high-pressure protection.

View the fix ->

PC04

PC04 means the inverter compressor drive reported an error. The compressor-drive electronics or compressor circuit need technician diagnosis.

AdvisoryTechnician

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Turn the system off with the remote, wait about 10 minutes, then power cycle once at the breaker or disconnect if you can do that safely. If the code returns, stop resetting and schedule service. Do not open the indoor or outdoor cabinet.
When to call a pro: Call a licensed HVAC technician if PC04 returns after one safe reset. Tell them Carrier identifies PC04 as inverter compressor drive error.

View the fix ->

PC0L

PC0L means low ambient temperature protection is active. The system is protecting itself because outdoor conditions are outside what it wants for that mode.

AdvisoryDIY

Sourced Jul 2026

Applies to: Comfort 22
Homeowner fix: Wait for outdoor conditions to move back within the unit's operating range and avoid forcing repeated restarts. Keep the outdoor unit clear of snow and loose debris.
When to call a pro: Call for service if PC0L appears when outdoor conditions are not unusually cold for the system, never clears, or another fault code appears.

View the fix ->