What It Means
P3 reports a malfunction of the thermistor located in the switch (electrical component) box — specifically the reactor thermistor that monitors temperature on the inverter's reactor component to prevent it from overheating.
Daikin SkyAir
Daikin SkyAir Error Code P3
Troubleshooting guide for the Daikin SkyAir system fault P3.
ACLogics Standardize SkyAir diagnostics See the commercial workflow → Standardize SkyAir diagnostics
Possible Causes
- Disconnected or loose reactor thermistor connector, open or shorted thermistor element, thermistor displaced from its mounting position on the reactor, defective inverter PCB sensor input circuit, wiring damage inside the switch box from heat or vibration.
Not sure which one it is — or if it's none of these? Try ACLogics today.
Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
New to this code? Click to see why this happens
Full Diagnosis
P3 reports a malfunction of the thermistor located in the switch (electrical component) box — specifically the reactor thermistor that monitors temperature on the inverter's reactor component to prevent it from overheating. This is a sensor-circuit fault distinct from L3/L4, which report an actual electrical component box or radiation fin temperature rise event rather than a failure of the sensor reading it. The outdoor unit stops the inverter compressor as a precaution when this thermistor signal is lost or out of range.
All Recorded Causes
Disconnected or loose reactor thermistor connector, open or shorted thermistor element, thermistor displaced from its mounting position on the reactor, defective inverter PCB sensor input circuit, wiring damage inside the switch box from heat or vibration.
Verify Before Replacing Parts
- Confirm the exact Daikin model family and skyair context before acting on a generic code description.
- Confirm board LEDs, wiring polarity, and model compatibility before replacing control boards — this Daikin fault points at disconnected or loose reactor thermistor connector, open or shorted thermistor element, th….
- Check for intermittent communication faults caused by connectors, moisture, or damaged harnesses, and rule out the next candidate on the list.
- After the correction, run the system long enough to confirm the skyair fault does not return under normal load.
Diagnosing SkyAir across a fleet?
ACLogics standardizes commercial SkyAir diagnostics across your whole team — consistent steps, less guesswork on every call.