Diagnosis
Remote control signal failure. Cause is typically dead batteries, signal obstruction, or infrared receiver fault.
How to Fix It
Replace the remote's batteries (2 AAA). Use fresh batteries, not recycled ones. Point the remote directly at the infrared sensor on the fan's control panel from within 15 feet. Ensure no physical obstruction between you and the fan. Test all buttons. Remove any protective film that may be covering the sensor on the fan.
If That Didn't Work
The infrared receiver on the fan's main PCB may be faulty. This is uncommon but possible. Test the remote on a smartphone camera: point the remote's LED at the camera and press a button. If you see a purple light flash on the phone screen, the remote is transmitting.
Heads Up
The remote uses line-of-sight infrared. It will not work if aimed at the back or sides of the fan. The sensor is only on the front control panel.