Hello,
The most common cause for smoking is candy or sugar floss residue forming on the device after use.If the device has been used multiple times without cleaning the residue can come into contact with the heating element. This build up is flammable so it will eventually smoke. Properly cleaning the extractor head and heating element is your best course of action.
more information can be found by following this link [[Nostalgia Electrics PCM805 Troubleshooting]]
Carlton.