Daikin Error Code and Repair Guides - 24 Guides
Daikin HVAC troubleshooting hub with 24 guides for fault codes, alarms, symptoms, parts checks, and repair decisions.
Use this page when your Daikin furnace, air conditioner, heat pump, or mini split is flashing a fault. Start with the exact code, then open the fix guide to diagnose airflow, ignition, sensor, pressure switch, board, or communication problems before you order parts or book a service call.
Tip: search the exact brand, model, and code together, for example "Daikin error code 13" or "Daikin pressure switch fault".
Start With These Daikin Guides
Daikin Chiller Fault Codes - EWAD, EWAQ, McQuay, and MicroTech Alarms Daikin chiller alarm guide for EWAD, EWAQ, McQuay, iOM, MicroTech, high-pressure, low-pressure, compressor, oil, and freeze faults. Daikin F9 Error Code: Causes and How to Fix It Daikin F9 error code explained: indoor coil thermistor faults, loose connectors, dislodged probes, resistance tests, and the fixes that clear the fault. Daikin H6 Error Code — Indoor Fan Motor Lock Fault Fix Daikin H6 indoor fan guide for locked motors, blower obstructions, capacitors, Hall sensors, control boards, ice, and VRV/VRF checks. Daikin RXYQ VRV Error Codes: Commercial Fault Guide Daikin RXYQ VRV faults cover pressure, EEV, compressor startup, refrigerant shortage, and F1/F2 transmission errors on commercial systems. Daikin VRV E7 Fan Motor Error Code Daikin VRV E7 fan-motor guide for locked rotors, fan inverter boards, blades, harness checks, DC motor tests, and pro repair limits. Daikin F3 Error Code: Discharge Thermistor Fault Daikin F3 points to the discharge temperature thermistor circuit. Test the sensor, connector, harness, and outdoor-board input before ordering parts.
Daikin FAQ
Where should I start with Daikin error codes?
Start with the exact Daikin model and displayed code or alarm, then open the closest guide on this page. Match the symptom, recent service history, and any secondary codes before resetting the equipment or ordering parts.
Do Daikin fault codes always mean a bad control board?
No. Many Daikin codes point to airflow, water flow, sensors, wiring, power quality, filters, switches, or operating conditions. Check the simple causes in the guide before replacing an expensive board.
When should I stop troubleshooting a Daikin fault myself?
Daikin HVAC equipment can hide unsafe ignition, refrigerant, high-voltage, or combustion problems behind a simple blinking code. Stop and use the repair checklist or compare service options when the guide points to gas, refrigerant, line voltage, sealed-system work, food-safety temperatures, or repeated faults after a reset.
| Error Code | What It Means | Guide |
|---|---|---|
| Daikin Chiller Fault Codes | EWAD, EWAQ, McQuay, and MicroTech Alarms | Fix → |
| Daikin F9 Error Code: Causes and How to Fix It | Daikin F9 error code explained: indoor coil thermistor faults, loose connectors, dislodged probes, resistance tests, and the fixes that clear the fault. | Fix → |
| Daikin H6 Error Code | Indoor Fan Motor Lock Fault Fix | Fix → |
| Daikin RXYQ VRV Error Codes: Commercial Fault Guide | Daikin RXYQ VRV faults cover pressure, EEV, compressor startup, refrigerant shortage, and F1/F2 transmission errors on commercial systems. | Fix → |
| Daikin VRV E7 Fan Motor Error Code | Daikin VRV E7 fan-motor guide for locked rotors, fan inverter boards, blades, harness checks, DC motor tests, and pro repair limits. | Fix → |
| Daikin F3 Error Code: Discharge Thermistor Fault | Daikin F3 points to the discharge temperature thermistor circuit. Test the sensor, connector, harness, and outdoor-board input before ordering parts. | Fix → |
| Daikin J3 Discharge Pipe Sensor Fault | Daikin J3 guide for discharge-pipe sensor faults, abnormal compressor temperature, thermistor testing, coil airflow, charge issues, and technician checks. | Fix → |
| Daikin Mini Split Error Codes | E, U, F, A Faults | Fix → |
| Daikin VRV System Error Codes | Daikin VRV error-code guide for U, E, A, C, F, and H faults. Check communication wiring, sensors, refrigerant pressure, drains, boards, and fan motors. | Fix → |
| Daikin Fit Error Codes | Inverter Heat Pump Diagnostic Guide | Fix → |
| Daikin RXQ VRV System Error Codes (Outdoor Unit): Complete Guide | Daikin RXQ VRV outdoor unit error codes and fault diagnostics. U-series fault codes, causes, and technician-level troubleshooting. | Fix → |
| Daikin A3 Error Code: Drain Pan and Pump Fault | Daikin A3 points to a full drain pan, clogged condensate line, failed pump, float switch problem, or poor indoor-unit slope. | Fix → |
| Daikin C4 Error Code: Indoor Coil Sensor Fault | Daikin C4 means the indoor coil thermistor is out of range. Check sensor seating, connector corrosion, thermistor resistance, and PCB input. | Fix → |
| Daikin C9 Discharge Sensor Error | Daikin C9 guide for compressor discharge-temperature sensor faults, loose connectors, bad thermistors, refrigerant issues, and outdoor PCB checks. | Fix → |
| Daikin E1 Error Code: Indoor Thermistor Fault | Daikin E1 points to an indoor temperature sensor fault. Check the thermistor, connector corrosion, indoor PCB input, moisture damage, and model match. | Fix → |
| Daikin E3 Error Code: Indoor Fan Motor Fault | Daikin E3 means the indoor fan speed is wrong or missing. Check wheel drag, coil buildup, motor feedback, wiring, and the indoor PCB. | Fix → |
| Daikin E7 Outdoor Fan Motor Error | Daikin E7 guide for outdoor fan motor faults, stalled blades, Hall feedback, motor windings, inverter-board output, connectors, and debris. | Fix → |
| Daikin E9 Error Code: Compressor Protection Fault | Daikin E9 points to compressor protection. Check refrigerant charge, outdoor coil airflow, compressor current, ambient limits, and inverter faults. | Fix → |
| Daikin L5 Error Code: Compressor Lock Fault | Daikin L5 means compressor startup failed or lock protection tripped. Check locked-rotor current, inverter output, wiring, and compressor condition. | Fix → |
| Daikin R-32 U4 Error Code: Communication Fault | Daikin R-32 U4 means indoor-outdoor communication failed. Check signal terminals, reversed wiring, cable damage, interference, and the inverter board. | Fix → |
| Daikin U2 Error Code: Undervoltage Protection Fault | Daikin U2 means supply voltage dropped too low. Check utility voltage, wire size, disconnect terminals, contactors, and compressor startup load. | Fix → |
| Daikin U4 Error Code: Low-Pressure Refrigerant Fault | Daikin U4 on this guide points to low pressure or refrigerant flow trouble. Check leaks, service valves, restrictions, and the pressure sensor. | Fix → |
| Daikin U9 Error Code: High-Pressure Trip Fault | Daikin U9 points to high pressure. Check outdoor coil blockage, fan motor speed, refrigerant overcharge, and non-condensables in the circuit. | Fix → |
| Daikin VRV/VRF U4 Communication Fault | Daikin VRV/VRF U4 guide for indoor-outdoor communication faults, F1/F2 wiring, termination resistors, PCB failures, power issues, and noise. | Fix → |