Daikin Air Conditioner Error C5

⚡ Quick Answer: The Daikin Air Conditioner C5 error signifies a communication failure between the indoor and outdoor units, typically due to a malfunctioning heat exc... ✅ DIY Fixable

What Does Error C5 Mean?

The Daikin Air Conditioner C5 error signifies a communication failure between the indoor and outdoor units, typically due to a malfunctioning heat exchanger temperature thermistor. This can prevent proper cooling or heating, causing the unit to stop operation and display the C5 code. Potential causes include a faulty thermistor, poor connector contact, or an indoor unit PCB signal processing fault.

Common Symptoms:

  • Unit stops operation and displays C5
  • Possible overheating/abnormal temperature sensing of heat exchanger
  • Indoor unit may not cool or heat properly due to sensor error

Possible Causes

  • Heat exchanger temperature thermistor failure (middle or gas pipe) (medium)
  • Thermistor connector poor contact or disconnection (medium)
  • Indoor unit PCB signal processing fault (low)

How to Fix Error C5

DIY Fix Basic checks before technician visit

  1. Turn off and isolate power to the unit
  2. Wait a few minutes and reset power to see if the error clears
  3. Check that the indoor unit intake and filters are clean (no heavy obstruction)

Technician Only Service heat exchanger temperature sensor and connections

  1. Disconnect power and open the indoor unit access panel
  2. Inspect and test the heat exchanger thermistor (middle or gas pipe thermistor) for correct resistance values
  3. Check thermistor connector and wiring for loose contacts or damage
  4. Replace faulty thermistor and re-test unit operation
  5. If thermistor and wiring are good, test indoor PCB for proper signal processing and replace if needed

Parts needed: Heat exchanger temperature thermistor, Indoor unit PCB (if required), Wiring/connectors

🛑 When to Call a Pro:
  • If error persists after basic reset and cleaning
  • If you are not trained to safely access internal components
  • If thermistor tests indicate abnormal resistance
  • If PCB diagnostics are necessary

Technical Specifications

wattage N/A
component Control Board
resistance N/A
part_number DAIKIN PCB-123456
voltage_rating 220V AC

Common Questions

What does C5 error mean on Daikin Air Conditioner?

C5 error indicates a communication failure between indoor and outdoor units, often linked to a sensor malfunction.

Can I fix Daikin Air Conditioner C5 error myself?

Yes, you can reset the unit and check for clean filters before calling a technician.

How much does it cost to fix C5 error?

Repair costs range from $150 to $450+, depending on parts and service region.

When should I call a technician for C5?

Call a technician if the error persists after basic checks or if you're unsure about accessing internal components.

Sources & References

Data last verified: 2026-07-01

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