F21 / Outdoor LED1 flashes 10 times — Abnormal of piping sensor / Outdoor coil temperature sensor

What does F21 mean?

The sensor measuring the temperature of the outdoor coil or piping is malfunctioning, which can affect the unit's ability to operate efficiently, especially during defrost cycles.

• Defrost temperature sensor issue
• Outdoor PCB issue

Click steps to track your progress.

1. 1

   Turn off the air conditioner at the main power switch or circuit breaker.

2. 2

   Wait for at least 30 seconds, then turn the power back on.

3. 3

   Ensure the outdoor unit is clear of any debris or ice buildup, especially around the coils.

4. 4

   If the error persists, contact a qualified technician.