Daikin Air Conditioner Error A4

⚡ Quick Answer: The Daikin air conditioner A4 error code indicates a communication failure between the indoor and outdoor units, often due to abnormal temperature rea... ✅ DIY Fixable

What Does Error A4 Mean?

The Daikin air conditioner A4 error code indicates a communication failure between the indoor and outdoor units, often due to abnormal temperature readings from the heat exchanger. This error can cause the unit to stop operating and display the A4 code on the remote or LEDs. It may also signify issues with the temperature sensor or heat exchanger itself.

Common Symptoms:

  • Unit stops operation and displays A4 on remote or LEDs
  • Possible abnormal temperature readings related to heat exchanger

Possible Causes

  • Abnormal temperature detected on primary heat exchanger (sensor reading outside expected range) (medium)

How to Fix Error A4

DIY Fix Basic checks for heat exchanger temperature abnormality

  1. Turn off the air conditioner and wait a few minutes before restarting to see if the error reoccurs.
  2. Ensure air filters are clean and airflow around the indoor and outdoor units is unobstructed.
  3. Check for ice buildup on the indoor or outdoor heat exchanger if in cooling mode.

Technician Only Inspect heat exchanger and temperature sensing components

  1. Use service tools to read detailed fault history and sensor readings.
  2. Test temperature sensors around the heat exchanger for continuity and correct values.
  3. Inspect heat exchanger coils for blockages, refrigerant flow issues, or physical damage.

Parts needed: Heat exchanger temperature sensor, Heat exchanger coil

🛑 When to Call a Pro:
  • If error reappears after basic restart
  • If other symptoms like vibration, noise, or no cooling/heating occur
  • If ice buildup or abnormal heat exchanger temperature persists

Next step

Choose the next step for A4

Confirm the diagnosis before ordering. An error code can identify the system involved, but it does not prove that a specific part has failed.

Other parts options

Check related components first; use model search as a fallback.

Model number required

Model-compatible Air Conditioner parts

Enter the complete model number to browse compatible replacement parts. This is a model-based parts search, not a diagnosis that a specific component failed.

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Optional routine care

Maintenance supplies

These products support cleaning or routine upkeep. They are separate from the possible repair components above and are not claimed to fix this error code or symptom.

Maintenance supply

Air Conditioner Fin Cleaner

For routine cleaning of accessible coil fins when permitted by the manufacturer. Disconnect power and follow product and appliance instructions.

View maintenance supply
Maintenance supply

Model-Compatible Washable AC Filter

A reusable filter option only where the appliance supports one. Match the full model, dimensions, and filter specification.

Compatibility check required: use the complete appliance model and compare the existing filter, bag, or specification before ordering.

Find one that fits my model

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Technical Specifications

wattage 2000W
component Control Board
resistance 5-15 ohms
part_number DAIKIN 4E-1B
voltage_rating 230V AC

Common Questions

What does A4 error mean on daikin air conditioner?

The A4 error indicates a communication failure between the indoor and outdoor units due to abnormal heat exchanger temperatures.

Can I fix daikin air conditioner A4 error myself?

Yes, you can perform basic checks like restarting the unit, cleaning air filters, and checking for ice buildup.

How much does it cost to fix A4 error?

Repair costs for the A4 error can range from ¥5,000 to ¥30,000 depending on the parts and model.

When should I call a technician for A4?

Call a technician if the error reappears after a restart, or if you notice vibrations, noise, or persistent ice buildup.

Sources & References

Data last verified: 2026-07-25

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