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
- Turn off and isolate power to the unit
- Wait a few minutes and reset power to see if the error clears
- Check that the indoor unit intake and filters are clean (no heavy obstruction)
Technician Only Service heat exchanger temperature sensor and connections
- Disconnect power and open the indoor unit access panel
- Inspect and test the heat exchanger thermistor (middle or gas pipe thermistor) for correct resistance values
- Check thermistor connector and wiring for loose contacts or damage
- Replace faulty thermistor and re-test unit operation
- 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
- 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
Next step
Choose the next step for C5
Confirm the diagnosis before ordering. An error code can identify the system involved, but it does not prove that a specific part has failed.
Most relevant component to inspect
Thermistor
Measures precise temperature changes and sends resistance feedback to the control board.
- Typical part-only price
- $15 - $35
- DIY difficulty
- Easy
- Estimated time
- 15-30 mins
Where can I find the model number?
Check the rating label around the door, lid, frame, rear panel, or inside the appliance cabinet. Use the complete model number, including suffixes.
Verify the complete model and part number on the retailer's compatibility page before ordering.
Other parts options
Check related components first; use model search as a fallback.
HVAC Control Board
Controls fan, compressor, sensor, and communication functions in the HVAC unit.
Wiring Harness
Connects controls, sensors, motors, and other electrical components inside the appliance.
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.
Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. We may earn a commission from other qualifying purchases or service requests made through links on this page, at no additional cost to you. Recommendations are based on repair relevance, not commission rate.
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.
Air Conditioner Fin Cleaner
For routine cleaning of accessible coil fins when permitted by the manufacturer. Disconnect power and follow product and appliance instructions.
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.
Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. Recommendations are based on routine-care relevance, not commission rate.
Technical Specifications
| note | The previous model-independent part specification was removed. Verify the full model number and diagnosis in the manufacturer's official parts catalog before ordering. |
|---|---|
| part_number | None |
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
- Daikin Error Code Search (global support) (official)
- Daikin C5 Error Explanation (Proshop Daikin) (community)
- Daikin C5 Sensor Fault Repair Discussion (community)
Data last verified: 2026-07-31
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