First check your batteries to see if they need to be replaced. Often times the remote will appear to be functioning when in reality the battery is not strong enough to send the transmission. Make sure the transmitter is on the same channel as the receiver in the fan, For the Casablanca Advantouch W-62 W-63 W-64 W-65 Turn the electricity off to the fan for over 30 secs, make sure the screen on remote is clear (not showing anything is on) turn electricity back on and depress the up and down arrows until you get a tone from the fan saying the signals are alligned. Comfort Touch W-21 remotes, turn off electricity, make sure screen is clear of any functions, turn electricity back on and wait 20secs then depress the auto and test buttons at the same time until "cc" appears on the screen. On the Prime Touch W-505 turn electricity off 30 secs then power back on, depress the high, med and low buttons 3 secs each INDIVIDUALLY and fan should turn on low speed.