I have 2 Hampton Bay fans that are identical with the same problem. The fans don't work but the lights do. They are both operated by remote control only. What could be the problem?

Do they have pullchains?

Ceiling fan remote controls - help and FAQ- Ceiling Fans N More

No, they do not have pull chains.

Replace remote batteries? If not that simple than call an electrician or simply replace the fans. Did they work at one time or is this a condition you came upon?

If the remote LEDs light up when you attempt to control the fan, it is likely that the receivers have gone bad. Contact the manufacturer for replacement parts.

Ceiling fan remote controls - help and FAQ- Ceiling Fans N More