DIAGNOSIS Smoke during preheating is caused by grease or food debris carbonizing on the exposed heating coil at the top of the cooking chamber.
FIX Unplug and let the unit cool completely. Use a damp cloth wrapped around a chopstick or non-metal tool to gently wipe the coil. Avoid applying pressure that could bend the coil. A mild vinegar-water solution can help dissolve grease.
IF THAT DIDN'T WORK For stubborn buildup, use a soft-bristle brush (like a clean toothbrush) to dislodge debris. Hold the fryer upside down over a trash can to let debris fall out. Do not spray cleaners directly into the unit.
HEADS UP Never submerge the main unit in water or use abrasive pads on the heating element. This can damage the coil and its protective coating, creating a fire hazard.