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ActronAir Air Conditioner Fault Codes

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What does your ActronAir fault code mean?

Pick the code showing on your remote, wall controller or indoor unit and see what it means, what commonly causes it, and what is safe to check yourself. This page covers 207 ActronAir fault codes for units sold in Australia, compiled from official Australian manufacturer and distributor documentation, the same references our own technicians carry.

Heads up: ActronAir uses the same code with different meanings on different product ranges, so check the model range shown next to the code.

Every ActronAir fault code at a glance

Some models show faults as a flashing-light pattern instead of a code; documented lamp patterns are listed alongside their codes.

Code	What it means	How serious	Most likely cause	What you can check yourself
CP (Aurora (SWB) and Serene (WRC/WRE) wall splits and multi-split indoor units (MRE/BRE) (shown as off by remote switch on multi-splits))	The remote on/off terminal is open, which usually means an external switch or energy management device has turned the unit off.	Normal operation	External demand response or remote switch active	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E0 (Aurora (SWB) and Serene (WRC/WRE) wall splits, Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems and multi-split indoor units (MRE/BRE) (1 lamp flash))also shown as 1 lamp flash	The indoor unit’s memory chip (EEPROM) has a parameter error.	Fault – service needed	Corrupted indoor board memory	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E0 (Multi-split outdoor units (MRC))	The outdoor unit’s memory chip (EEPROM) has a parameter error.	Fault – service needed	Corrupted outdoor board memory	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E0 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	A power phase sequence error or phase failure has been detected (three phase units).	Fault – service needed	A phase lost at the switchboard	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E01 (Classic 2 (CRA/CCA/EVA/EAA/EFA), Advance (CRV/EVV/EAA/EFV) and Aires (CRS/EVA) ducted systems (NEO, LR7-1 and LC7-2 wall controllers))	The indoor fan is not running at the speed the system asked for (fan RPM feedback error).	Fault – service needed	Blocked return air filter overloading the fan	Clean or check the return air filter is not clogged
*E09 (Classic 2, ESP Platinum (shown as E9), Advance, Aires and QUE ducted systems)also shown as E9*	The low pressure safety switch has tripped, usually because the system is low on refrigerant.	Fault – service needed	Low refrigerant charge (possible leak)	Clean or check the return air filter is not clogged
E1 (Aurora (SWB) and Serene (WRC/WRE) wall splits, Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (indoor and outdoor displays, including the UltraSlim R-32 outdoor display), multi-split indoor units (MRE/BRE) (2 lamp flashes) and the WC-02 wired controller)also shown as 2 lamp flashes	The indoor and outdoor units have lost communication with each other.	Fault – service needed	Damaged or loose interconnecting cable	Check the outdoor unit isolator switch (next to the outdoor unit) is switched on
E10 (ESP Platinum, Advance, Aires and QUE ducted systems)	The low pressure sensor has failed (open or short circuit).	Minor fault	Faulty low pressure sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E100 (Advance ducted systems)	The drive’s PFC circuit has tripped a hardware overcurrent protection.	Fault – service needed	Drive power electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E100 (Aires ducted systems)	The compressor drive’s charging circuit has a malfunction.	Fault – service needed	Drive electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E101 (Advance and Aires ducted systems)	The drive’s PFC circuit has tripped a software overcurrent protection.	Fault – service needed	Drive power electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E102 (Advance and Aires ducted systems)	The drive’s PFC circuit has detected excessive voltage.	Fault – service needed	Mains voltage surge	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E103 (Advance ducted systems with the R-32 (Uno Pro board) outdoor unit and Aires ducted systems)also shown as E103**	The drive’s power module temperature reading is abnormally low or its sensor is open circuit.	Minor fault	Faulty temperature sensor in the drive	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E104 (Advance ducted systems with the R-32 (Uno Pro board) outdoor unit and Aires ducted systems)also shown as E104**	The drive has locked itself out after reaching its fault limit and needs to be reset and checked.	Fault – service needed	Repeated drive protection trips	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E11 (Classic 2, ESP Platinum, Advance, Aires and QUE ducted systems)	The high pressure safety switch has tripped, usually because the outdoor unit cannot get rid of heat.	Fault – service needed	Blocked or dirty outdoor coil	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E12 (ESP Platinum, Advance, Aires and QUE ducted systems)	The high pressure sensor has failed (open or short circuit).	Minor fault	Faulty high pressure sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E13 (Advance ducted systems with the R-410A (Uno board) outdoor unit; QUE three phase systems can show the same meaning under E13)also shown as E13*	The outdoor drive’s HSP connector jumper pin is missing or disconnected.	Fault – service needed	Jumper pin dislodged or not fitted on the VSD HSP connector	Turn the system off at the isolator for 5 minutes, then restart it once. This fault usually needs a technician to reseat the connector.
E13 (Advance, Aires and QUE three phase ducted systems)	The outdoor unit’s compressor drive has reported an internal error.	Fault – service needed	Compressor drive (VSD) fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E14 (ESP Platinum and QUE single phase ducted systems)	The condenser pressure is too low for normal operation.	Fault – service needed	Low refrigerant charge (possible leak)	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E15 (ESP Platinum, Advance, Aires and QUE ducted systems)	The outdoor unit has lost communication with its compressor speed drive (VSD).	Fault – service needed	Loose or damaged wiring between the outdoor board and drive	Check the outdoor unit isolator switch (next to the outdoor unit) is switched on
E17 (ESP Platinum and QUE single phase ducted systems)	A fault has been detected in one of the outdoor unit’s peripheral devices.	Fault – service needed	Faulty outdoor accessory or sensor circuit	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*E18 (ESP Platinum, Advance, Aires and QUE ducted systems (E18 open circuit, E19 short circuit on ESP Platinum and QUE single phase))also shown as E19*	The suction temperature sensor has failed or is giving an abnormal reading.	Minor fault	Faulty suction temperature sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E2 (Multi-split outdoor units (MRC))	The indoor and outdoor units have lost communication with each other.	Fault – service needed	Damaged or loose interconnecting cable	Check the outdoor unit isolator switch (next to the outdoor unit) is switched on
E2 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The room temperature sensor (T1) has failed.	Minor fault	Faulty room temperature sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E2 (ESP Digital and ESP Plus ducted systems (SRD/SRV) with LM7 or LM24 wall controller)	The indoor coil outlet temperature sensor has failed (open or short circuit).	Minor fault	Faulty or disconnected indoor coil-out sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E22 (ESP Platinum, Advance, Aires and QUE ducted systems)	The outdoor ambient temperature sensor has failed, and the unit may run in a reduced safe mode.	Minor fault	Faulty ambient temperature sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E23 (ESP Platinum and QUE single phase ducted systems)	The outdoor unit has lost communication with its electronic expansion valve (EEV) board, and the unit runs in safe mode.	Fault – service needed	Loose or damaged wiring to the EEV board	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E25 (ESP Platinum and QUE single phase ducted systems)	The outdoor temperature reading has not updated, which is a status message rather than a breakdown.	Normal operation	Temporary sensor communication dropout	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E26 (ESP Platinum, Advance, Aires and QUE ducted systems)	The compressor drive has detected excessive electrical current and shut down to protect itself.	Fault – service needed	Compressor working too hard due to blocked airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E27 (ESP Platinum, Advance, Aires and QUE ducted systems)	The compressor drive has detected the incoming voltage is too high.	Fault – service needed	Mains supply voltage too high	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E28 (ESP Platinum, Advance, Aires and QUE ducted systems)	The compressor drive electronics are running too hot.	Fault – service needed	Blocked outdoor unit airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E29 (ESP Platinum, Advance, Aires and QUE ducted systems)	The compressor drive has detected the incoming voltage is too low.	Fault – service needed	Low mains supply voltage (brownout)	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E3 (Aurora (SWB) and Serene (WRC/WRE) wall splits, Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems and multi-split indoor units (MRE/BRE) (4 lamp flashes))also shown as 4 lamp flashes	The indoor fan is not running at the correct speed.	Fault – service needed	Faulty indoor fan motor	Clean or check the return air filter is not clogged
E3 (Multi-split outdoor units (MRC))	The outdoor unit’s inverter (IPM) board has lost communication with the main outdoor control board.	Fault – service needed	Loose or damaged wiring between outdoor boards	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E3 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The indoor coil outlet temperature sensor (T2A) has failed.	Minor fault	Sensor open or short circuit	Turn the system off at the isolator for 5 minutes, then restart it once
*E3 (Ducted systems on LM7, LM24, LM-ZC, LR7, LC7, NEO and Que controllers (Classic, Classic 2, ESP Digital/Plus, ESP Platinum, Advance, Aires, QUE))also shown as E03*	A room temperature sensor has failed (open or short circuit), so the system cannot read the room temperature properly.	Minor fault	Faulty wall controller or remote room sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E30 (ESP Platinum, Advance, Aires and QUE ducted systems)	The compressor drive has locked itself out after repeated faults and needs to be reset and checked.	Fault – service needed	Repeated drive protection trips	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E31 (ESP Platinum and QUE single phase ducted systems)	The compressor drive has reported an internal error.	Fault – service needed	Drive electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*E32 (ESP Platinum and QUE single phase ducted systems)also shown as E33*	The system tripped on high or low refrigerant pressure measured by the drive’s pressure sensors (envelope protection).	Fault – service needed	Blocked outdoor coil or restricted airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E34 (ESP Platinum and QUE single phase ducted systems)	The unit has reduced its output because the compressor drive is running hot (derating).	Minor fault	Hot weather and heavy use	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E35 (ESP Platinum and QUE single phase ducted systems)	The unit has reduced its output because the suction pressure is low (derating).	Minor fault	Low refrigerant charge (possible leak)	Clean or check the return air filter is not clogged
E36 (ESP Platinum and QUE single phase ducted systems)	The unit has reduced its output because the condenser pressure is low (derating).	Minor fault	Very cold outdoor conditions	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E37 (ESP Platinum and QUE single phase ducted systems)	The unit has reduced its output because the condenser pressure is high (derating).	Minor fault	Blocked or dirty outdoor coil	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E38 (ESP Platinum and QUE single phase ducted systems)	The unit has reduced its output to stay within its power limit (derating).	Normal operation	Heavy demand in extreme weather	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E39 (ESP Platinum and QUE single phase ducted systems)	A defrost cycle took too long to complete and timed out.	Minor fault	Very cold or wet outdoor conditions	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E4 (Aurora (SWB) and Serene (WRC/WRE) wall splits, Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems and multi-split indoor units (MRE/BRE) (5 lamp flashes))also shown as 5 lamp flashes	The indoor room temperature sensor (T1) has failed (open or short circuit).	Minor fault	Faulty room temperature sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E4 (Multi-split outdoor units (MRC))	An outdoor temperature sensor (coil T3, ambient T4, discharge T5 or indoor coil outlet pipe T2B) has failed.	Minor fault	Faulty temperature sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E4 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The indoor coil outlet pipe temperature sensor (T2B) has failed.	Minor fault	Faulty pipe sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E4 (Ducted systems on LM7, LM24, LR7, LC7, NEO and Que controllers (Classic, Classic 2, ESP Digital/Plus, ESP Platinum, Advance, Aires, QUE; the QUE three phase table reads it as the indoor coil out sensor))also shown as E04	The indoor coil temperature sensor has failed (open or short circuit).	Minor fault	Faulty indoor coil sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E40 (ESP Platinum and QUE single phase ducted systems)	The compressor drive is restarting too frequently, which points to an underlying problem.	Fault – service needed	Power supply interruptions	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E41 (ESP Platinum, Advance, Aires and QUE ducted systems)	The compressor drive’s internal DC voltage is too low.	Fault – service needed	Low or unstable mains supply	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E42 (Advance, Aires and QUE three phase ducted systems)	The system shut down to protect the compressor because the evaporating pressure fell extremely low (envelope protection).	Fault – service needed	Low refrigerant charge (possible leak)	Clean or check the return air filter is not clogged
E43 (Advance, Aires and QUE three phase ducted systems)	The system shut down to protect the compressor because the compression ratio was too high (envelope protection).	Fault – service needed	Blocked outdoor coil in cooling	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E44 (Advance, Aires and QUE three phase ducted systems)	The system shut down because the condensing pressure was too high (envelope protection).	Fault – service needed	Blocked or dirty outdoor coil	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E45 (Advance, Aires and QUE three phase ducted systems)	The system shut down because the compression ratio was too low (envelope protection).	Fault – service needed	Mild conditions with low load	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E47 (Advance, Aires and QUE three phase ducted systems)	The compressor hit its torque limit and the system shut down to protect it.	Fault – service needed	Compressor under mechanical stress	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E5 (Aurora (SWB) and Serene (WRC/WRE) wall splits, Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems and multi-split indoor units (MRE/BRE) (6 lamp flashes))also shown as 6 lamp flashes	The indoor coil temperature sensor (T2) has failed (open or short circuit).	Minor fault	Faulty evaporator coil sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E5 (Multi-split outdoor units (MRC))	The supply voltage to the outdoor unit is too high or too low.	Fault – service needed	Mains voltage problems (brownout or surge)	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E5 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	An outdoor temperature sensor (T3 coil or TP discharge) has failed.	Minor fault	Faulty outdoor sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*E5 (Classic (SRA/SRE/SRG), ESP Digital/Plus (SRD/SRV) and ESP Platinum ducted systems; QUE single phase shows E05 on the outdoor display)also shown as E05*	The indoor and outdoor units have lost communication with each other.	Fault – service needed	Power interruption to the outdoor unit	Check the outdoor unit isolator switch (next to the outdoor unit) is switched on
E50 (Advance, Aires and QUE three phase ducted systems)	The outdoor control board is not configured correctly for the unit.	Fault – service needed	Board replaced without correct setup	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E51 (Classic 2, Advance, Aires and QUE ducted systems (NEO, LR7-1, LC7-2 or Que controllers))	The indoor and outdoor units have lost communication with each other.	Fault – service needed	Damaged or loose communication cable between units	Check the outdoor unit isolator switch (next to the outdoor unit) is switched on
E52 (Classic 2, Advance, Aires and QUE ducted systems (NEO, LR7-1, LC7-2 or Que controllers))	The indoor unit has lost communication with the wall controller.	Fault – service needed	Loose or damaged controller cable	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E53 (QUE ducted systems with Que zoning (single and three phase))	The indoor unit has lost communication with the zone (VAV) module.	Fault – service needed	Loose or damaged zone module wiring	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E55 (Classic 2, Advance and Aires ducted systems (NEO, LR7-1 or LC7-2 wall controller))	The outdoor unit has lost communication with the building management system (BMS) interface.	Minor fault	Loose or damaged BMS wiring	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E56 (Classic 2, Advance and Aires ducted systems (NEO, LR7-1 or LC7-2 wall controller))	The system cannot find a master wall controller.	Fault – service needed	Wall controller not set as master	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E6 (Multi-split outdoor units (MRC))	The power factor correction (PFC) module in the outdoor unit has tripped a protection.	Fault – service needed	Power quality problems	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E6 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The indoor circuit board’s zero crossing check has failed (a power signal fault on the board).	Fault – service needed	Indoor control board fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*E6 (Most ActronAir ducted systems (Classic, ESP Digital/Plus, ESP Platinum, Advance, Aires, QUE; LM7, LM24, LR7, NEO and Que controllers))also shown as E06*	The compressor discharge temperature is too high, which often means the system is low on refrigerant.	Fault – service needed	Low refrigerant charge (possible leak)	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E60 (Advance, Aires and QUE three phase ducted systems)	The compressor drive has detected excessive current in a compressor phase and shut down.	Urgent – turn it off	Compressor winding or wiring fault	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E61 (Advance and Aires ducted systems)	The compressor drive has lost one of the compressor’s output phases.	Fault – service needed	Loose or damaged compressor wiring	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E62 (Advance, Aires and QUE three phase ducted systems)	The compressor drive’s internal DC bus voltage is too high.	Fault – service needed	Mains voltage surge	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E63 (Advance, Aires and QUE three phase ducted systems)	The compressor drive’s internal DC bus voltage is too low.	Fault – service needed	Low or unstable mains supply	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E64 (Advance ducted systems)	The compressor drive has lost track of the compressor rotor and stopped it.	Fault – service needed	Compressor drive fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E65 (Advance ducted systems)	The current sensor for the compressor’s U phase has failed.	Fault – service needed	Faulty current sensor in the drive	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E65 (Aires ducted systems)	The compressor drive has detected a compressor phase loss fault.	Fault – service needed	Loose or damaged compressor wiring	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E66 (Advance ducted systems with the R-410A (Uno board) outdoor unit and QUE three phase systems)also shown as E66*	The incoming AC supply voltage is imbalanced between phases or an input phase has been lost.	Fault – service needed	A phase lost at the switchboard	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E67 (Advance ducted systems with the R-410A (Uno board) outdoor unit and QUE three phase systems)also shown as E67*	The compressor drive’s inverter has tripped a de-saturation (hardware overcurrent) protection.	Fault – service needed	Drive power electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E68 (Advance ducted systems)	The current sensor for the compressor’s V phase has failed.	Fault – service needed	Faulty current sensor in the drive	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E69 (Advance, Aires and QUE three phase ducted systems)	The drive’s power factor correction (PFC-IGBT) module is running too hot.	Fault – service needed	Blocked outdoor unit airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E7 (Serene (WRC/WRE) wall splits and multi-split indoor units (MRE/BRE))	The indoor unit’s display board has lost communication with the main indoor circuit board.	Minor fault	Loose or damaged display cable	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E7 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The indoor unit’s memory chip (EEPROM) has a fault.	Fault – service needed	Corrupted indoor board memory	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*E7 (Most ActronAir ducted systems (Classic, Classic 2, ESP Digital/Plus, ESP Platinum, Advance, Aires, QUE; LM7, LM24, LR7, NEO and Que controllers))also shown as E07*	The outdoor coil temperature sensor has failed (open or short circuit).	Minor fault	Faulty outdoor coil sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E70 (Advance, Aires and QUE three phase ducted systems)	The compressor drive has lost the compressor rotor position and stopped it.	Fault – service needed	Compressor drive fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E71 (Advance, Aires and QUE three phase ducted systems)	The compressor motor temperature sensor (thermistor) has failed.	Minor fault	Faulty motor temperature sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E72 (Advance, Aires and QUE three phase ducted systems)	The drive’s precharge relay is stuck open, so the drive cannot power up properly.	Fault – service needed	Drive relay fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E73 (Advance and Aires ducted systems)	The current sensor for the compressor’s W phase has failed.	Fault – service needed	Faulty current sensor in the drive	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E74 (Advance and Aires ducted systems)	The drive has tripped on IGBT overcurrent, which can point to a choke wiring problem or failure.	Urgent – turn it off	Choke wiring problem or choke failure	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E74 (QUE three phase ducted systems)	The compressor drive has detected excessive current in a compressor phase and shut down.	Urgent – turn it off	Compressor winding or wiring fault	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E75 (Advance, Aires and QUE three phase ducted systems)	The drive kept reducing compressor speed because of high phase current until it timed out (foldback timeout).	Fault – service needed	Compressor working too hard due to blocked airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E76 (Advance, Aires and QUE three phase ducted systems)	The drive kept reducing output because its power module was too hot until it timed out (foldback timeout).	Fault – service needed	Blocked outdoor unit airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E77 (Advance, Aires and QUE three phase ducted systems)	The drive kept reducing output because of high AC input current until it timed out (foldback timeout).	Fault – service needed	Heavy demand in extreme weather	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E78 (Advance and Aires ducted systems)	The drive’s power factor correction (PFC-IGBT) module temperature is abnormally low.	Minor fault	Very cold outdoor conditions	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E78 (QUE three phase ducted systems)	The drive’s automatic configuration communication has timed out.	Fault – service needed	Loose or damaged wiring between outdoor boards	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E79 (Advance and Aires ducted systems)	The drive has tripped a hardware overcurrent (IPM) protection on the compressor.	Urgent – turn it off	Drive power electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*E8 (Cascade (URC/CRE) and UltraSlim (URC/LRE) twin systems (indoor display, 9 lamp flashes))also shown as 9 lamp flashes*	The master and slave indoor units of a twin system have lost communication with each other.	Fault – service needed	Interconnecting cable fault between the twin indoor units	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E8 (Multi-split outdoor units (MRC))	The outdoor fan is not running at the correct speed.	Fault – service needed	Faulty outdoor fan motor	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E8 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The indoor fan controller is out of control (the fan is not responding correctly).	Fault – service needed	Faulty indoor fan motor	Clean or check the return air filter is not clogged
*E8 (ESP Digital/Plus, ESP Platinum, Advance, Aires and QUE ducted systems (not the original Classic series))also shown as E08*	The outdoor discharge temperature sensor has failed (open or short circuit).	Minor fault	Faulty discharge sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E80 (Advance, Aires and QUE three phase ducted systems)	The compressor motor temperature is too high.	Fault – service needed	Compressor working too hard due to blocked airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E81 (Advance, Aires and QUE three phase ducted systems)	The compressor drive’s control board temperature is too high.	Fault – service needed	Blocked outdoor unit airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E82 (Advance, Aires and QUE three phase ducted systems)	The compressor drive’s power module temperature is too high.	Fault – service needed	Blocked outdoor unit airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E83 (Advance, Aires and QUE three phase ducted systems)	The drive’s power factor correction (PFC-IGBT) module temperature is too high.	Fault – service needed	Blocked outdoor unit airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E84 (Advance, Aires and QUE three phase ducted systems)	Communication has been lost between two processors (DSP and PFC) inside the compressor drive.	Fault – service needed	Drive electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E85 (Advance, Aires and QUE three phase ducted systems)	Communication has been lost between the drive’s communications processor and its DSP.	Fault – service needed	Drive electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E86 (Advance and QUE three phase ducted systems)	The current drawn by the compressor phases is imbalanced.	Fault – service needed	Compressor winding fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E87 (Advance and QUE three phase ducted systems)	The current in the drive’s three phase PFC circuit is imbalanced.	Fault – service needed	Uneven supply voltage between phases	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E88 (Advance ducted systems with the R-32 (Uno Pro board) outdoor unit, Aires and QUE three phase systems)also shown as E88**	The compressor drive has a microelectronics or memory (EEPROM) fault.	Fault – service needed	Drive electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E89 (Advance and QUE three phase ducted systems)	The compressor motor ran over its speed limit and the drive shut it down.	Fault – service needed	Drive control fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*E9 (Cascade (URC/CRE) and UltraSlim (URC/LRE) twin systems (indoor display, 10 lamp flashes))also shown as 10 lamp flashes*	Another indoor unit in the twin system has a fault.	Fault – service needed	A fault on the other indoor unit of the twin pair	Check the other indoor unit’s display for its own fault code and look that code up
E9 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The main indoor circuit board has lost communication with the display board.	Minor fault	Loose or damaged display cable	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E9 (Classic (SRA/SRE/SRG) and ESP Digital/Plus (SRD/SRV) ducted systems with LM7 or LM24 wall controller)	A refrigerant pressure switch has tripped on high or low pressure, or a power phase problem has been detected (phase faults on three phase units).	Fault – service needed	Blocked outdoor coil or restricted airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E90 (Advance, Aires and QUE three phase ducted systems)	The drive is configured for the wrong compressor model.	Fault – service needed	Drive replaced without correct setup	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E91 (Advance, Aires and QUE three phase ducted systems)	The temperatures measured inside the inverter are imbalanced.	Fault – service needed	Drive electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E92 (Advance, Aires and QUE three phase ducted systems)	The temperatures measured in the drive’s PFC circuit are imbalanced.	Fault – service needed	Drive electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E93 (Advance and Aires ducted systems)	The compressor motor temperature reading is abnormally low.	Minor fault	Very cold outdoor conditions	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E94 (Advance and Aires ducted systems)	The compressor drive’s board temperature reading is abnormally low.	Minor fault	Very cold outdoor conditions	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E95 (Advance and Aires ducted systems)	The drive’s power module temperature reading is abnormally low or its sensor has failed (open or short circuit).	Minor fault	Faulty temperature sensor in the drive	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E96 (Advance ducted systems)	The drive’s power factor correction (PFC-IGBT) module temperature is abnormally low.	Minor fault	Very cold outdoor conditions	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E96 (Aires ducted systems)	The temperature sensing circuit for the drive’s PFC module has a malfunction.	Minor fault	Drive electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E97 (Advance ducted systems)	The drive’s communications analog to digital converter (ADC) has failed.	Fault – service needed	Drive electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E97 (Aires ducted systems)	A processor chip (IC) inside the compressor drive has reset unexpectedly.	Fault – service needed	Drive electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E98 (Advance and Aires ducted systems)	A current sensor or current sensing circuit in the compressor drive has failed.	Fault – service needed	Faulty current sensor in the drive	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E99 (Advance ducted systems)	The compressor drive has tripped on compressor overload.	Fault – service needed	Compressor working too hard due to blocked airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
E99 (Aires ducted systems)	The compressor drive has reported a malfunction outside the standard list.	Fault – service needed	Drive electronics fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
E99 (QUE single phase ducted systems)	The system shut down on compressor envelope protection.	Fault – service needed	Operating pressures outside safe limits	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
EA (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The compressor has tripped its overload protection (recorded after 4 trips).	Fault – service needed	Compressor working too hard due to blocked airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
EB (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The inverter power module (IPM) has a malfunction.	Fault – service needed	Inverter module fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*EC (Aurora (SWB) and Serene (WRC/WRE) wall splits and Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (7 lamp flashes))also shown as 7 lamp flashes*	The system has detected a possible refrigerant leak.	Urgent – turn it off	Refrigerant leak in the piping or coils	Stop using the unit and switch it off at the isolator or breaker
EC (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The air clean function has a malfunction.	Minor fault	Air clean module fault	Turn the system off at the isolator for 5 minutes, then restart. Cooling and heating usually still work while this fault is present.
*EC07 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 12 lamp flashes*	The outdoor fan is running outside its normal speed range (some models).	Fault – service needed	Faulty outdoor fan motor	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
*EC0D (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 14 lamp flashes*	The outdoor unit has reported a malfunction; the outdoor display carries the detailed code.	Fault – service needed	Any outdoor unit fault (pressure, temperature or drive protection)	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
*EC51 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 5 lamp flashes*	The outdoor unit’s memory chip (EEPROM) has a parameter error.	Fault – service needed	Corrupted outdoor board memory	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*EC52 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 5 lamp flashes*	The outdoor coil temperature sensor (T3) has failed (open or short circuit).	Minor fault	Faulty condenser coil sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*EC53 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 5 lamp flashes*	The outdoor air temperature sensor (T4) has failed (open or short circuit).	Minor fault	Faulty outdoor ambient sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*EC54 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 5 lamp flashes*	The compressor discharge temperature sensor (TP) has failed (open or short circuit).	Minor fault	Faulty discharge sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*EC56 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes (free-match indoor units))also shown as 5 lamp flashes*	The evaporator coil outlet temperature sensor (T2B) has failed (open or short circuit).	Minor fault	Faulty pipe sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
ED (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The outdoor unit has a protection fault; the outdoor display carries the detailed code.	Fault – service needed	Any outdoor unit fault (pressure, temperature or drive protection)	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
EE (Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems and multi-split indoor units (MRE/BRE) (cassette and ducted units, 8 lamp flashes); shown as EE full water alarm on the WC-02 wired controller)also shown as 8 lamp flashes	The condensate water level alarm has activated, meaning the drain system cannot get rid of water.	Fault – service needed	Blocked condensate drain	Turn the unit off to stop further dripping
EF (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	A fault outside the standard list has been detected (other fault).	Minor fault	Miscellaneous indoor or outdoor fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*EH00 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as EH0A, 1 lamp flash*	The indoor unit’s memory chip (EEPROM) has a parameter error.	Fault – service needed	Corrupted indoor board memory	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*EH03 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 4 lamp flashes*	The indoor fan is running outside its normal speed range (some models).	Fault – service needed	Faulty indoor fan motor	Clean or check the return air filter is not clogged
*EH0E (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes (cassette and ducted units))also shown as 13 lamp flashes*	The condensate water level alarm has activated, meaning the drain system cannot get rid of water.	Fault – service needed	Blocked condensate drain	Turn the unit off to stop further dripping
*EH0b (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 9 lamp flashes*	The two processor chips on the indoor unit have lost communication with each other.	Minor fault	Indoor control board fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*EH3A (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes (units with an external fan module))also shown as 4 lamp flashes*	The external fan module’s DC bus voltage is too low.	Fault – service needed	Low or unstable mains supply	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*EH3b (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes (units with an external fan module))also shown as 4 lamp flashes*	The external fan module’s DC bus voltage is too high.	Fault – service needed	Mains voltage surge	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*EH60 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 6 lamp flashes*	The indoor room temperature sensor (T1) has failed (open or short circuit).	Minor fault	Faulty room temperature sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*EH61 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 6 lamp flashes*	The indoor coil temperature sensor (T2) has failed (open or short circuit).	Minor fault	Faulty evaporator coil sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
EHbA (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes (units with an external fan module))	The external fan module has lost communication with the indoor unit.	Minor fault	Loose or damaged fan module wiring	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*EL01 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 2 lamp flashes*	The indoor and outdoor units have lost communication with each other.	Fault – service needed	Damaged or loose interconnecting cable	Check the outdoor unit isolator switch (next to the outdoor unit) is switched on
*EL0C (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 8 lamp flashes*	The system has detected a possible refrigerant leak (some models).	Urgent – turn it off	Refrigerant leak in the piping or coils	Stop using the unit and switch it off at the isolator or breaker
F0 (Serene (WRC/WRE) wall splits and Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (some units, 1 lamp flash); also the outdoor display on Cascade, UltraSlim and UltraSlim R-32 systems)also shown as 1 lamp flash	Overcurrent or overload protection has tripped.	Urgent – turn it off	Power surge or unstable supply voltage	Turn the system off at the isolator for 5 minutes, then restart it once. If F0 returns, leave the system off.
F0 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The wired wall controller has lost communication with the indoor unit.	Fault – service needed	Loose or damaged controller cable	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
F1 (Aurora (SWB) and Serene (WRC/WRE) wall splits, Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (indoor and outdoor displays, including the UltraSlim R-32 outdoor display) and multi-split indoor units (MRE/BRE) (2 lamp flashes))also shown as 2 lamp flashes	The outdoor air temperature sensor (T4) has failed (open or short circuit).	Minor fault	Faulty outdoor ambient sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
F1 (Multi-split outdoor units (MRC))	The coil outlet temperature sensor for indoor unit A has failed.	Minor fault	Faulty pipe sensor on that indoor unit	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
F1 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The elevating fascia panel has not closed properly.	Minor fault	Something obstructing the panel	Check nothing is stopping the fascia panel from closing fully
F2 (Aurora (SWB) and Serene (WRC/WRE) wall splits, Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (indoor and outdoor displays, including the UltraSlim R-32 outdoor display) and multi-split indoor units (MRE/BRE) (3 lamp flashes))also shown as 3 lamp flashes	The outdoor coil temperature sensor (T3) has failed (open or short circuit).	Minor fault	Faulty condenser coil sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
F2 (Multi-split outdoor units (MRC))	The coil outlet temperature sensor for indoor unit B has failed.	Minor fault	Faulty pipe sensor on that indoor unit	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
F3 (Aurora (SWB) and Serene (WRC/WRE) wall splits, Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (indoor and outdoor displays, including the UltraSlim R-32 outdoor display) and multi-split indoor units (MRE/BRE) (4 lamp flashes))also shown as 4 lamp flashes	The compressor discharge temperature sensor (T5) has failed (open or short circuit).	Minor fault	Faulty discharge sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
F3 (Multi-split outdoor units (MRC))	The coil outlet temperature sensor for indoor unit C has failed.	Minor fault	Faulty pipe sensor on that indoor unit	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
F4 (Aurora (SWB) and Serene (WRC/WRE) wall splits, Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (indoor and outdoor displays, including the UltraSlim R-32 outdoor display) and multi-split indoor units (MRE/BRE) (5 lamp flashes))also shown as 5 lamp flashes	The outdoor unit’s memory chip (EEPROM) has a parameter error.	Fault – service needed	Corrupted outdoor board memory	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
F4 (Multi-split outdoor units (MRC))	The coil outlet temperature sensor for indoor unit D has failed.	Minor fault	Faulty pipe sensor on that indoor unit	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
F5 (Aurora (SWB) and Serene (WRC/WRE) wall splits, Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (indoor and outdoor displays, including the UltraSlim R-32 outdoor display) and multi-split indoor units (MRE/BRE) (6 lamp flashes))also shown as 6 lamp flashes	The outdoor fan is not running at the correct speed.	Fault – service needed	Faulty outdoor fan motor	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
F5 (Multi-split outdoor units (MRC))	The coil outlet temperature sensor for indoor unit E has failed.	Minor fault	Faulty pipe sensor on that indoor unit	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*F6 (Cascade and UltraSlim free-match indoor units and multi-split indoor units (MRE/BRE) (7 lamp flashes))also shown as 7 lamp flashes*	The indoor coil outlet pipe temperature sensor (T2B) has failed (open or short circuit).	Minor fault	Faulty pipe sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*F7 (Cascade slim cassettes with an auto-lifting panel (8 lamp flashes))also shown as 8 lamp flashes*	The auto-lifting panel has lost communication with the slim cassette unit.	Minor fault	Loose or damaged panel cable	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*F8 (Cascade slim cassettes with an auto-lifting panel (9 lamp flashes))also shown as 9 lamp flashes*	The auto-lifting panel mechanism is faulty.	Minor fault	Panel lifting motor fault	Check nothing is caught in or hanging from the panel
*F9 (Cascade slim cassettes with an auto-lifting panel (10 lamp flashes))also shown as 10 lamp flashes*	The auto-lifting panel has not closed properly.	Minor fault	Something obstructing the panel	Check nothing is stopping the panel from closing fully
J0 (Cascade (URC/CRE), UltraSlim (URC/LRE) and UltraSlim R-32 (URC/LRE/LRC) systems (outdoor unit display))	The evaporator coil temperature is too high and the unit has stopped to protect itself.	Fault – service needed	Restricted indoor airflow	Clean or check the return air filter is not clogged
J1 (Cascade (URC/CRE), UltraSlim (URC/LRE) and UltraSlim R-32 (URC/LRE/LRC) systems (outdoor unit display))	The condenser coil temperature is too high and the unit has stopped to protect itself.	Fault – service needed	Blocked or dirty outdoor coil	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
J2 (Cascade (URC/CRE), UltraSlim (URC/LRE) and UltraSlim R-32 (URC/LRE/LRC) systems (outdoor unit display))	The compressor discharge temperature is too high and the unit has stopped to protect itself.	Fault – service needed	Low refrigerant charge (possible leak)	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
J3 (Cascade (URC/CRE), UltraSlim (URC/LRE) and UltraSlim R-32 (URC/LRE/LRC) systems (outdoor unit display))	The power factor correction (PFC) module in the outdoor unit has tripped a protection.	Fault – service needed	Power quality problems	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
J4 (Cascade (URC/CRE), UltraSlim (URC/LRE) and UltraSlim R-32 (URC/LRE/LRC) systems (outdoor unit display))	The outdoor unit’s main board has lost communication with the compressor drive board.	Fault – service needed	Loose or damaged wiring between outdoor boards	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
J5 (Cascade (URC/CRE), UltraSlim (URC/LRE) and UltraSlim R-32 (URC/LRE/LRC) systems (outdoor unit display))	The high pressure protection has tripped, usually because the outdoor unit cannot get rid of heat.	Fault – service needed	Blocked or dirty outdoor coil	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
J6 (Cascade (URC/CRE), UltraSlim (URC/LRE) and UltraSlim R-32 (URC/LRE/LRC) systems (outdoor unit display))	The low pressure protection has tripped, usually because the system is low on refrigerant.	Fault – service needed	Low refrigerant charge (possible leak)	Clean or check the return air filter is not clogged
J8 (Cascade (URC/CRE), UltraSlim (URC/LRE) and UltraSlim R-32 (URC/LRE/LRC) systems (outdoor unit display))	The incoming AC power voltage is outside safe limits and the unit has stopped.	Fault – service needed	Mains voltage problems (brownout or surge)	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
LP (UltraSlim R-32 (URC/LRE/LRC) systems (outdoor unit display))	The unit has stopped because the outdoor temperature is too low for safe operation.	Normal operation	Extremely cold outdoor conditions	Wait until the outdoor temperature rises, then restart the unit
P0 (Aurora (SWB) and Serene (WRC/WRE) wall splits, Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (indoor and outdoor displays, including the UltraSlim R-32 outdoor display) and multi-split indoor units (MRE/BRE) (1 lamp flash))also shown as 1 lamp flash	The inverter power module (IPM) has detected a fault or excessive current and shut the compressor down.	Fault – service needed	Inverter module fault	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
P0 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The evaporator (indoor coil) temperature protection has tripped.	Minor fault	Blocked return air filter	Clean or check the return air filter is not clogged
P1 (Aurora (SWB) and Serene (WRC/WRE) wall splits, Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (indoor and outdoor displays, including the UltraSlim R-32 outdoor display) and multi-split indoor units (MRE/BRE) (2 lamp flashes))also shown as 2 lamp flashes	The supply voltage to the unit is too high or too low.	Fault – service needed	Mains voltage problems (brownout or surge)	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
P1 (Multi-split outdoor units (MRC): models MRC-100AS-4, MRC-110AS-5 and MRC-135AS-5 only)	The high pressure protection has tripped, usually because the outdoor unit cannot get rid of heat.	Fault – service needed	Blocked or dirty outdoor coil	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
P1 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The unit is in defrost or anti-cold-draught mode, which is normal operation rather than a fault.	Normal operation	Normal defrosting of the outdoor coil in cold weather	Wait 5 to 15 minutes for the cycle to finish
P2 (Aurora (SWB) and Serene (WRC/WRE) wall splits (Aurora SWB52C and SWB70C only), Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems and the UltraSlim R-32 outdoor display (3 lamp flashes))also shown as 3 lamp flashes	The compressor (or on some models the inverter module) has overheated and the unit has shut down to protect it.	Fault – service needed	Low refrigerant charge (possible leak)	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
P2 (Multi-split outdoor units (MRC): models MRC-100AS-4, MRC-110AS-5 and MRC-135AS-5 only)	The low pressure protection has tripped, usually because the system is low on refrigerant.	Fault – service needed	Low refrigerant charge (possible leak)	Clean or check the return air filter is not clogged
P2 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The condenser temperature protection has tripped.	Fault – service needed	Blocked or dirty outdoor coil	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
*P3 (Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (indoor and outdoor displays, 4 lamp flashes))also shown as 4 lamp flashes*	The unit has stopped because the outdoor temperature is too low for safe operation.	Normal operation	Extremely cold outdoor conditions	Wait until the outdoor temperature rises, then restart the unit
P3 (Multi-split outdoor units (MRC))	The outdoor unit is drawing too much electrical current and has shut down to protect itself.	Urgent – turn it off	Compressor working too hard due to blocked airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
P3 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The compressor temperature protection has tripped.	Fault – service needed	Low refrigerant charge (possible leak)	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
P4 (Aurora (SWB) and Serene (WRC/WRE) wall splits, Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (indoor and outdoor displays, including compressor rotor position protection, and the UltraSlim R-32 outdoor display) and multi-split indoor units (MRE/BRE) (5 lamp flashes))also shown as 5 lamp flashes	The inverter compressor drive has reported an error and stopped the compressor.	Fault – service needed	Compressor drive fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
P4 (Multi-split outdoor units (MRC); also shown as P4 (discharge pipe temperature protection) on the WC-02 wired controller)	The compressor discharge temperature is too high and the unit has stopped to protect the compressor.	Fault – service needed	Low refrigerant charge (possible leak)	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
*P5 (Multi-split systems (MRE/BRE indoor units, 6 lamp flashes))also shown as 6 lamp flashes*	Two indoor units are asking for opposite modes (one heating, one cooling), which the system cannot do at the same time.	Normal operation	Indoor units set to conflicting modes	Set all indoor units to the same mode (all cooling or all heating) on their remotes
P5 (Multi-split outdoor units (MRC))	The condenser temperature is too high and the unit has stopped to protect itself.	Fault – service needed	Blocked or dirty outdoor coil	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
P5 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The discharge high pressure protection has tripped.	Fault – service needed	Blocked or dirty outdoor coil	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
*P6 (Multi-split systems (MRE/BRE indoor units, 7 lamp flashes))also shown as 7 lamp flashes*	The outdoor unit has tripped on a high or low refrigerant pressure fault (the outdoor display shows J5 for high pressure or J6 for low pressure).	Fault – service needed	Blocked outdoor coil or restricted airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
*P6 (Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (indoor display, 7 lamp flashes))also shown as 7 lamp flashes*	The compressor voltage protection has tripped.	Fault – service needed	Mains voltage problems (brownout or surge)	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
P6 (Multi-split outdoor units (MRC))	The inverter power module (IPM) has tripped a protection and stopped the compressor.	Fault – service needed	Inverter module fault	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
P6 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The discharge low pressure protection has tripped, usually because the system is low on refrigerant.	Fault – service needed	Low refrigerant charge (possible leak)	Clean or check the return air filter is not clogged
*P7 (Cascade (URC/CRE) and UltraSlim (URC/LRE) split ducted and cassette systems (indoor and outdoor displays, 8 lamp flashes) and the UltraSlim R-32 outdoor display)also shown as 8 lamp flashes*	The outdoor inverter (IGBT) temperature sensor is faulty (open or short circuit).	Minor fault	Faulty IGBT temperature sensor	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
P7 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The over-voltage protection has tripped.	Fault – service needed	Mains supply voltage too high	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
P8 (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	The compressor overload protection has tripped.	Fault – service needed	Compressor working too hard due to blocked airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
*PC00 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 7 lamp flashes*	The inverter power module has detected a fault or excessive current and shut the compressor down.	Fault – service needed	Inverter module fault	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
*PC01 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 2 lamp flashes*	The supply voltage to the unit is too high or too low.	Fault – service needed	Mains voltage problems (brownout or surge)	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
*PC02 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 3 lamp flashes*	The compressor or inverter module has overheated and the unit has shut down to protect itself.	Fault – service needed	Low refrigerant charge (possible leak)	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
*PC03 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 7 lamp flashes*	The system has tripped on a high or low refrigerant pressure fault (some models).	Fault – service needed	Blocked outdoor coil or restricted airflow	Look at the outdoor unit and make sure leaves, grass or objects are not blocking the airflow (do not open the unit)
*PC04 (Cascade R-32 (URC/CRC) and UltraSlim R-32 (URC/LRE/LRC) systems; Serene Series 2 R-32 wall splits show the same codes)also shown as 5 lamp flashes*	The inverter compressor drive has reported an error and stopped the compressor.	Fault – service needed	Compressor drive fault	Turn the system off at the isolator or breaker, wait 5 minutes, then restart it
PF (Systems with the WC-02 wired wall controller (Cascade and UltraSlim ducted and cassette units))	A fault has occurred elsewhere in the system; check the indoor or outdoor unit display for the detailed code.	Minor fault	Any indoor or outdoor unit fault not shown on the controller	Check the indoor and outdoor unit displays for their own fault code and look that code up
dF (Serene Series 2 wall split indoor units (also shown as dEF on ducted outdoor displays))	The unit is running a normal defrost cycle in heating mode, not a fault.	Normal operation	Normal defrosting of the outdoor coil on cold mornings	Wait 5 to 15 minutes for the defrost cycle to finish

Codes that mean switch the system off

If your ActronAir unit shows EC, F0, P3, EL0C, E60, E74, E74, E79, turn the system off at the isolator and leave it off. These faults involve the compressor, refrigerant or electrical protection, and running the unit can cause further damage.

The most serious ActronAir fault codes explained