Daikin Mini Split Error Code C5: How to Fix It

Q: What causes Daikin error code C5?

Error code C5 is caused by a faulty indoor heat exchanger thermistor (R3T). This can result from sensor degradation over time, physical damage, loose wiring connections, or contamination preventing proper temperature sensing.

Q: Can I reset Daikin error code C5?

You can temporarily clear the error by turning the unit off for 5 minutes, but C5 will return if the underlying thermistor problem isn't fixed. The thermistor must be tested and replaced if faulty for a permanent solution.

Q: How much does it cost to fix Daikin C5 error?

DIY repair costs $20-50 for a replacement thermistor. Professional repair typically costs $150-300 including parts and labor. The thermistor itself is inexpensive, but labor costs vary by location and system accessibility.

Q: Will my Daikin mini split work with C5 error?

The unit may continue running but with reduced efficiency and poor temperature control. The system cannot accurately sense evaporator temperature, leading to potential short cycling, inadequate cooling/heating, and increased energy consumption.

Q: How do I prevent Daikin C5 error from happening again?

Prevent C5 errors through regular maintenance including cleaning air filters monthly, annual coil cleaning, and ensuring proper airflow. Replace thermistors every 5-7 years as preventive maintenance, and schedule annual professional inspections.

Abstract

Daikin error code C5 indicates a malfunction with the indoor heat exchanger thermistor (R3T), which measures the temperature of the evaporator coil. This sensor failure prevents your mini split from properly regulating temperature and can cause cooling or heating performance issues.