DIY HVAC Tools

Concord mini split error codes

Concord ductless systems (4DHV outdoor units with DWH wall-mount indoor units) come from Allied Air, the Lennox family company behind Armstrong Air, AirEase, Ducane and Concord. They are Midea-built and use the Midea code set; the service manual lists the same E, F and P table with the matching outdoor LED flash counts.

Covers: 4DHV outdoor with DWH wall-mount indoor (2016 and later).

Type it exactly as the unit shows it. Not sure which brand? It is printed on the front of the indoor unit.

Most looked-up Concord codes

E1Communication error between indoor and outdoor unitsE5Evaporator coil temperature sensor (T2) open or short circuitECRefrigerant leak detected (low refrigerant charge)P4Inverter compressor drive errorF1Outdoor ambient temperature sensor (T4) open or short circuitE4Indoor room temperature sensor (T1) open or short circuitP1Over-voltage or under-voltage protection

All Concord codes

25 codes. Type to filter the list.

CodeMeaningTypeFix
E0Indoor unit EEPROM parameter errorFaultDIY checks
E1Communication error between indoor and outdoor unitsFaultDIY checks
E2Zero-crossing signal detection errorFaultDIY checks
E3Indoor fan speed out of control (indoor fan motor fault)FaultDIY checks
E4Indoor room temperature sensor (T1) open or short circuitFaultDIY checks
E5Evaporator coil temperature sensor (T2) open or short circuitFaultDIY checks
ECRefrigerant leak detected (low refrigerant charge)FaultDIY checks
F0Overload current protection (compressor over-current)ProtectionDIY checks
EBCommunication error between indoor main board and display boardFaultDIY checks
EFIntelligent eye (occupancy sensor) module errorFaultDIY
F1Outdoor ambient temperature sensor (T4) open or short circuitFaultDIY checks
F2Condenser coil temperature sensor (T3) open or short circuitFaultDIY checks
F3Compressor discharge temperature sensor (TP) open or short circuitFaultDIY checks
F4Outdoor unit EEPROM parameter errorFaultTechnician
F5Outdoor fan speed out of control (outdoor fan motor fault)FaultDIY checks
P0Inverter module (IPM) malfunctionProtectionTechnician
P1Over-voltage or under-voltage protectionProtectionDIY checks
P2High temperature protection (compressor top or inverter module)ProtectionDIY checks
P3Outdoor temperature too low protection (heating lockout)ProtectionDIY
P4Inverter compressor drive errorProtectionTechnician
P5Mode conflict (multi-zone)ProtectionDIY
P6Outdoor low pressure protectionProtectionDIY checks
dFDefrost cycle runningStatusDIY
CLFilter cleaning reminderStatusDIY
APWi-Fi pairing (access point) modeStatusDIY

How Concord shows error codes

The code appears on the indoor unit's LED display in place of the set temperature. Some models also blink the indicator lamps in a pattern that matches the code. E codes are faults in the indoor unit or its communication link, F codes are faults on the outdoor side, and P codes are protections: the outdoor unit has stopped itself to prevent damage. EC is the refrigerant leak check.

Brands built on the same platform

These brands share a code table with Concord because the same factory builds them, so their pages describe the same faults: ACiQ, AirEase, Arcoaire, Arctic King, Armstrong Air, Blueridge, Bosch, Bryant, Carrier, Comfortmaker, Day & Night, Della, Ducane, Heil.

Sources

  • Allied Air 4DHV Mini-Split Series Service Manual 508067-01 (2016), Table 14 Indoor and Outdoor Unit Error Codes

Updated September 2026. Manufacturer site: www.concordair.com