F8 - 1 red flash, 3 green flashes — No input detected at outdoor unit

What does F8 mean?

This error means the outdoor unit is not receiving the expected input signals, pointing towards a potentially defective outdoor board.

• Defective outdoor unit board
• Wiring issues preventing signal transmission
• Lack of power to the outdoor unit

Click steps to track your progress.

1. 1

   Check that the outdoor unit is receiving power.

2. 2

   Inspect all wiring connections going to the outdoor unit.

3. 3

   Ensure no fuses or breakers controlling the outdoor unit have tripped.

4. 4

   If the problem continues, the outdoor board likely needs replacement.