Mitsubishi Mini-Split Error Code P2: How to Fix It

Q: Can I run my Mitsubishi mini-split with error P2?

It is not recommended. The system may not cool or heat properly and could run inefficiently or cause damage. It's best to fix the issue promptly.

Q: What is a 10k ohm NTC thermistor?

NTC stands for Negative Temperature Coefficient. A 10k ohm NTC thermistor decreases its resistance as temperature rises, allowing the control board to measure coil temperature.

Q: Can a dirty air filter cause error P2?

A dirty filter restricts airflow, which can affect coil temperature readings, but it typically triggers other errors like P6 (freeze protection). P2 specifically indicates an open thermistor circuit, not a temperature range issue.

Q: How do I test the indoor coil thermistor?

Disconnect it and measure resistance with a multimeter. At room temp (~77°F) it should be about 10k ohms. If it reads infinite (open) or very high resistance, it's faulty.

Q: Will error P2 clear itself after replacing the thermistor?

Yes, once the faulty thermistor is replaced and the system is powered on, the error code should clear automatically if the new sensor is working correctly.

Abstract

Error code P2 on your Mitsubishi mini-split signals that the indoor coil thermistor (temperature sensor) has an open circuit, meaning it's no longer sending a proper signal. This prevents the system from detecting the coil temperature and can cause the unit to stop cooling or heating. The fix typically involves checking the wiring or replacing the thermistor.