Carrier Heat Pumps

The amber LED flashes once for one second, then has a longer two-second pause. This signifies the unit is in a variable capacity range cutback due to pressure trips, high load, flank loading, or oil circulation issues. The system will attempt to self-recover.

The amber LED flashes once, then pauses. This indicates the unit is operating in variable capacity mode, which is a normal state.

Communication has been lost between system components. This can be caused by loose or shorted wiring, a user interface that isn't powered, a data bus locked up by power issues, or a damaged outdoor unit (ODU) control board.

The system has detected an invalid model plug. This can mean the wrong plug is installed, the plug itself is damaged, or the outdoor unit (ODU) control board is faulty.

The high pressure switch has opened, indicating a high pressure event within the system. The system will attempt to self-mitigate. Persistent high pressure conditions will lead to a lockout (Error Code 84). The system will reset after 15 minutes.

The system has detected a low pressure event. It will attempt to self-mitigate. Persistent low pressure conditions will lead to a lockout (Error Code 83). The system will reset after 15 minutes.

A fault has been detected in the compressor windings, specifically indicating a grounded compressor. This suggests internal damage to the compressor. The system will reset after 15 minutes.

The system has experienced a brownout event due to low line voltages. The unit will revert to a 5-minute cycle delay to protect components. This may indicate an issue with your power supply.

The system is locked out for 120 minutes (2 hours) due to persistent loss of communication with the inverter. This can stem from loose or damaged harnesses, contactor issues, or faulty ODU control or inverter drive components.

The 230VAC contactor has momentarily dropped out. This could be due to wiring issues, voltage glitches, or a damaged inverter drive. The system will revert to a 5-minute cycle delay.

The Outdoor Air Temperature (OAT) sensor is reporting a fault. This can be due to a disconnected, broken, or damaged sensor or wiring.

The Suction Temperature (OST) sensor is reporting a fault. This can be due to a disconnected, broken, or damaged sensor or wiring, or incorrect sensor placement.

A fault has been detected with the coil temperature sensor. This could be due to a disconnected harness, a broken wire, an improperly attached sensor, a damaged sensor, or hardware damage to the outdoor unit (ODU) control.

The Outdoor Air Thermistor (OAT) or Outdoor Coil Thermistor (OCT) readings are outside their expected range. This is often caused by improper sensor installation or placement, such as the sensor body touching sheet metal.

A fault has been detected with the suction pressure sensor. This could be caused by a disconnected harness, broken wire, an electrical short, or heat damage during brazing. The system will reset after 15 minutes.

Communication has been lost between the outdoor unit (ODU) circuit board and the inverter. The system will attempt to self-mitigate. Persistent conditions will lead to lockout (Error Code 48). The system will reset after 10 minutes.

The compressor scroll temperature is outside its normal operating range. This can be caused by various system issues or restrictions. The system will reset after 15 minutes.

The compressor is unable to start. This may be due to a high pressure differential between the high and low sides or mechanical damage to the compressor. The system will retry to start after 15 minutes.

The system is currently warming up the compressor sump temperature. This is a normal operation and typically takes up to 2 hours. Secondary heat might be requested if necessary during this period.

An internal fault has occurred within the inverter. This could be caused by noisy line voltage, a short circuit in the system, or a damaged inverter. The system will reset after 15 minutes.

The compressor motor temperature is outside its normal operating range. This is most likely due to a shorted sensor circuit. The system will reset after 5 minutes.

The system has detected a high suction gas temperature. It will attempt to recover from current spikes and self-correct. Persistent over current trips will eventually lead to Error 82 'Suction Over Temp Lockout'. The system will reset after 15 minutes.

The inverter temperature is outside its operating limits. The system will try to ride through temperature spikes and self-recover. Persistent over current trips will lead to Error 88 'Inverter Temp Lockout'. The system will reset after 15 minutes.

High current spikes have been measured by the inverter drive. The system will try to ride through these spikes and self-recover. Persistent over current trips will lead to Error 95 'High Current Lockout'. The system will reset after 15 minutes.

The compressor is not pumping. This can occur if the inverter output leads to the compressor are miswired, causing the compressor to run backward, or if the leads are not properly attached. The system will reset after 5 minutes.

The system is locked out for 4 hours due to persistent high suction gas temperature. Common causes include an overcharge of refrigerant, high load conditions, or an improperly matched system. This is a protective measure.

The system is locked out for 4 hours due to persistent low pressure events. This can be caused by cooling in low ambient conditions, an undercharged system, insufficient indoor airflow, or closed service valves.

The system is locked out for 4 hours due to persistent high pressure events. This can be caused by various factors including an overcharged system, airflow restrictions, closed service valves, or a faulty high pressure switch.

The system has entered a lockout state due to the compressor temperature being out of range multiple times (Error 59 or 71). The unit will attempt to ride through current spikes and self-recover, but persistent issues lead to this lockout.

A fault with the compressor temperature sensor has been detected. This can be due to a disconnected, improperly seated, or damaged sensor harness or the sensor itself. (Applies to software version 5 and earlier)

A fault with the inverter cable has been detected. This can be due to loose input power wires or a loose communication harness between the inverter and the circuit board. (Applies to software version 9 and later)

The system has entered a lockout state because the inverter temperature limits were exceeded multiple times (Error 75). This can be due to blocked heat exchangers, low airflow, or operation outside normal ranges.

The inverter drive has measured high DC voltage spikes. The system will attempt to ride through these spikes and self-recover.

The inverter drive has measured low DC voltage dropouts. The system will attempt to ride through these dropouts and self-recover.

The inverter drive has measured low AC voltage dropouts (230VAC). The system will try to ride through these dropouts and self-recover.

The inverter drive has measured high AC voltage spikes (230VAC). The system will try to ride through these spikes and self-recover.

The system has entered a lockout state due to high current. This can be caused by high supply line voltage, storm weather, loose wiring, incorrect compressor grounding, or inverter/compressor damage.

The system has entered a lockout state due to high torque. This can be caused by various factors including operating outside normal ranges, restrictions, overcharge, non-condensibles, or issues with service valves or airflow.

The Amber LED is continuously flashing, indicating the system is operating in Emergency Mode. This occurs when a regular thermostat is used instead of an Infinity User Interface, limiting the system to nominal (fixed speed) capacity.

The Amber LED is continuously on, indicating that the system is in Standby/Charging mode. This is a normal operating status and does not require troubleshooting.