If the fan will not turn at full speed, then check the speed indicator on the fan controller. Is the top LED illuminated when pressing the top of the fan speed bar multiple times?
My Decora Smart® Wi-Fi Fan Controller Will Not Allow My Fan To Turn At Full Speed
If the LED will move to the highest position:
The issue is between the fan controller and the motor. If the fan is controlled by a pull chain, then the most likely issue is the fan is not set to it's highest speed. Use the pull chain to set to the fan to the highest speed. Once the fan is set to high it is recommended that you no longer use the pull chain to control the fan speed. For additional troubleshooting steps consult the article Will My Ceiling Fan Work With The DW4SF Fan Speed Controller?
If the LED will not move to the top position:
This issue is likely that the Max Level in the app was lowered from the high position. This may be desirable if a fan wobbles at high speed.
To check the app setting, tap the ⋮ on the fan icon and then tap Settings.
Select Preset Fan Speed Options and confirm that Maximum Fan Speed is set to MAX. Slick Save if necessary.
