Cause of error code Fan speed low/high

1. The actual fan RPM is 30% lower than what is being called for. 
2. Blown fuse.

Solution for error code Fan speed low/high

1. -Vent/air intake lengths exceed the maximum allowed lengths.
- Check for obstruction or blockage in the vent/air intake pipes or at terminations.
- Check the wiring connections at the fan and at the main control board. 
- Replace the fan. 
- Replace the main control board.

2. Replace fuse F2 on the control board,