Heat Pump
Daikin Heat Pump error codes
59 codes across 1 model family. Start with your model number, because Daikin reuses the same numbers for different faults on different boards.
Daikin shares code tables with other brands
Daikin furnaces use Goodman control platforms, so Goodman model families apply. Daikin VRV IV heat pumps and Daikin mini split and thermostat codes are entirely separate systems with their own code tables.
Find your model family
The model number is on the data plate, usually on the side or back of the unit or behind the service panel. It usually starts with the letters or numbers in the name below.
59 codes
The RXTQ outdoor unit serves VRV indoor units over a shared communication bus, and the factory splits the code list by which unit reports it. A and C codes come from indoor units, E, F, H, J, L and P from the outdoor unit, and U and M are system or centralized controller faults. This is a commercial and light commercial multi split platform, not a residential one indoor mini split unit.
| Code | What it means | How urgent |
|---|---|---|
| A0 | Indoor unit external protection device abnormality | High |
| A1 | Indoor unit control board abnormality | High |
| A3 | Drain level control system abnormality | Moderate |
| A6 | Indoor fan motor lock or overload | High |
| A7 | Swing flap motor abnormality, warning | Low |
| A8 | Indoor unit power supply voltage abnormality | High |
| A9 | Indoor unit electronic expansion valve abnormality | High |
| AF | Drain water level above the limit, warning | Low |
| AH | Self cleaning decoration panel abnormality | Moderate |
| AJ | Capacity setting error | Moderate |
| C1 | Transmission abnormality between the indoor and fan boards | High |
| C4 | Indoor heat exchanger liquid pipe thermistor abnormality | Moderate |
| C5 | Indoor heat exchanger gas pipe thermistor abnormality | Moderate |
| C6 | Indoor unit and fan board combination error | High |
| C9 | Suction air thermistor abnormality | Moderate |
| CA | Discharge air thermistor abnormality | Moderate |
| CC | Humidity sensor system abnormality, warning | Low |
| CE | Infrared presence or floor sensor error, warning | Low |
| CJ | Remote controller thermistor abnormality, warning | Low |
| E1 | Outdoor unit main board abnormality | High |
| E3 | High pressure switch activation | High |
| E4 | Low pressure protection activation | High |
| E5 | Compressor motor lock | High |
| E7 | Outdoor fan motor abnormality | High |
| E9 | Outdoor electronic expansion valve abnormality | High |
| F3 | Discharge pipe temperature abnormality | High |
| F6 | Refrigerant overcharge | High |
| H9 | Outdoor air thermistor abnormality, R1T | Moderate |
| J3 | Discharge pipe thermistor abnormality, R2T | Moderate |
| J5 | Suction pipe thermistor abnormality, R3T and R5T | Moderate |
| J6 | Outdoor heat exchanger deicer thermistor abnormality, R4T | Moderate |
| J7 | Outdoor heat exchanger liquid pipe thermistor abnormality, R7T | Moderate |
| J9 | Subcooling heat exchanger gas pipe thermistor abnormality, R6T | Moderate |
| JA | High pressure sensor abnormality | High |
| JC | Low pressure sensor abnormality | High |
| L1 | Inverter board abnormality | High |
| L4 | Radiation fin temperature rise abnormality | High |
| L5 | Compressor instantaneous overcurrent | High |
| L8 | Compressor overcurrent | High |
| L9 | Compressor startup abnormality | High |
| LC | Transmission error between the outdoor board microcomputers | High |
| P1 | Inverter circuit capacitor high voltage | High |
| P4 | Radiation fin thermistor abnormality, warning | Low |
| U0 | Refrigerant shortage, warning that should not be ignored | High |
| U2 | Power supply insufficient or instantaneous abnormality | High |
| U3 | Check operation not executed | Moderate |
| U4 | Transmission error between indoor and outdoor units | High |
| U5 | Transmission error between the controller and the indoor unit | Moderate |
| U8 | Transmission error between main and sub controllers | Moderate |
| U9 | Transmission error within the same system | High |
| UA | Improper indoor and outdoor unit combination | High |
| UC | Centralized controller address duplication, warning | Low |
| UE | Transmission error between the centralized controller and an indoor unit | High |
| UF | System not set yet | Moderate |
| UH | System address undefined | High |
| M1 | Centralized controller board defect | High |
| M8 | Transmission error between centralized controllers | Moderate |
| MA | Poor centralized controller combination | Moderate |
| MC | Address duplication and poor setting, warning | Low |
Common questions
- How many Daikin heat pump error codes are documented here?
- 59 codes across 1 model family. Every code page lists what the fault means, the causes, the checks you can safely do yourself, and when it stops being worth resetting the unit.
- How do I read the code on a Daikin heat pump?
- The control board prints the code as text, so you read it off the display rather than counting anything. Write the exact characters down, including any letter, because Daikin codes are short and easy to misread.
- Which Daikin heat pump model do I have?
- The model number is on the data plate, usually on the side or back of the unit or behind the service panel. The family on this page are VRV IV RXTQ-TA / RXTQ-TB. The model number starts with the letters or numbers in that name, which is the only reliable way to pick the right code table.
- Do other brands share Daikin heat pump codes?
- Daikin furnaces use Goodman control platforms, so Goodman model families apply. Daikin VRV IV heat pumps and Daikin mini split and thermostat codes are entirely separate systems with their own code tables.