Daikin Air Conditioner Error P4
⚡ Quick Answer: The Daikin air conditioner P4 error code indicates a communication failure between the indoor and outdoor units, primarily due to an abnormality in th... ✅ DIY Fixable
What Does Error P4 Mean?
The Daikin air conditioner P4 error code indicates a communication failure between the indoor and outdoor units, primarily due to an abnormality in the outdoor unit's temperature sensor (radiation/heat sink fin thermistor). This can lead to the outdoor unit stopping operation, error displays on the indoor remote, and possible cooling inefficiencies.
Common Symptoms:
- Outdoor unit stops operation
- Error displayed on indoor remote/display
- Possible cooling inefficiency or shutdown
Possible Causes
- Faulty radiation/heat sink fin thermistor (temperature sensor) (high)
- Loose or defective thermistor connector/wiring (medium)
- Outdoor unit control/PCB abnormality affecting temperature reading (medium)
- Outdoor fan motor or heat dissipation issue (especially during cooling) (medium)
How to Fix Error P4
DIY Fix Basic power cycle
- Turn off the air conditioner using the remote or unit switch
- Disconnect power at plug or breaker
- Wait ~1 minute
- Restore power and restart the unit
Technician Only Inspect and test outdoor thermistor and connections
- Access outdoor unit
- Test the radiation/heat sink fin thermistor resistance and temperature response
- Inspect and secure thermistor connectors and wiring harness
- Replace thermistor if faulty
Parts needed: thermistor (radiation/heat sink fin), connector harness
Technician Only Evaluate outdoor control board and fan operation
- Diagnose outdoor inverter/control PCB for faults
- Test outdoor fan motor and verify proper heat dissipation
- Repair or replace defective components
Parts needed: outdoor control/PCB, fan motor
- If error persists after basic power cycle
- If outdoor unit fan isn’t running or odd noises are present
- If thermistor readings are out of specification
Technical Specifications
| wattage | N/A |
|---|---|
| component | Communication Cable |
| resistance | N/A |
| part_number | DAIKIN 4P-1.5MM |
| voltage_rating | 230V AC |
Common Questions
What does P4 error mean on daikin air conditioner?
The P4 error indicates a communication failure, often due to a faulty outdoor temperature sensor.
Can I fix daikin air conditioner P4 error myself?
You can try a basic power cycle by turning off the unit and disconnecting power for about a minute.
How much does it cost to fix P4 error?
Repair costs range from ¥5,000 to ¥20,000 for parts, plus additional labor charges.
When should I call a technician for P4?
Call a technician if the error persists after a power cycle or if you hear odd noises from the outdoor unit.
Sources & References
- Daikin NZ P4 fault definition (official)
- Daikin AC P4 error details (Japanese) (community)
- Daikin error code P4 explanation (airconland.jp) (community)
Data last verified: 2026-07-01
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