Daikin Mini Split Error Code C7: How to Fix It

Medium 30-60 minutes Medium Severity Verified June 2026
Error Code
C7
Brand
Daikin
Product Type
mini_split
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
30-60 minutes
Error code C7 on your Daikin mini split indicates a short circuit in the indoor air thermistor (R1T). This sensor monitors the temperature of the air returning to the indoor unit. A short usually means the sensor is faulty or its wiring is damaged. This guide will help you diagnose and fix the issue safely.
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Tools You'll Need

How to Fix Error Code C7

  1. Turn Off Power to the Unit

    Always disconnect power before servicing. Capacitors can hold dangerous voltage.
  2. Locate the R1T Thermistor

  3. Inspect the Thermistor and Wiring

  4. Measure Resistance with a Multimeter

    Be careful not to short the multimeter probes.
  5. Replace the Thermistor if Shorted

    Use a genuine or compatible replacement part to avoid future issues.
  6. Reassemble and Test

Parts You May Need

Daikin Air Thermistor (R1T replacement)
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Daikin Air Thermistor (R1T replacement)
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Daikin Air Thermistor (R1T replacement)
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Daikin Air Thermistor (R1T replacement)
Check Price on Amazon
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When to Call a Professional

If you are uncomfortable working with electrical components, if the thermistor replacement does not clear the error, or if you suspect the control board is faulty, call a licensed HVAC technician.

Frequently Asked Questions

What does error code C7 mean on a Daikin mini split?
Error C7 indicates a short circuit in the indoor air thermistor (R1T), which measures the temperature of the air entering the indoor unit. A short usually means the sensor is faulty or its wiring is damaged.
Can I still use my Daikin mini split with error C7?
It is not recommended. The system may not operate correctly or may refuse to run to prevent damage. Continuing to use it could cause inefficient cooling or additional system issues.
How much does it cost to fix Daikin error C7?
If you do it yourself, the cost is typically $10–$30 for a replacement thermistor. Hiring a professional may cost $100–$200 including service call and parts.
How do I test the R1T thermistor?
Use a multimeter set to ohms. Disconnect the thermistor from the control board and measure its resistance. At room temperature (77°F/25°C), it should read about 10-15 kΩ. A reading of 0 Ω indicates a short; OL indicates an open circuit.
Where is the R1T thermistor located?
The R1T thermistor is typically located inside the indoor unit, near the evaporator coil or in the air intake path. You may need to remove the front panel and air filter to access it.