Introduction
This guide is related to the Blender Smoking page. If the smells aren't accompanied by visible smoke, continue reading this page.
Almost every electrical appliance with a motor will emit some kind of smell for a short time after first use, so if this is the case, give the blender a chance to burn off the excess lubricant.
Causes
A blender that is working too hard processing frozen foods, hard nuts, thick butters, flax seeds, cell phones, glow sticks, etc. will be working harder and may eventually burnout or stall.
Your blender may be equipped with a thermal breaker that shuts down the motor if it starts overheating, so while there's little risk of fire, the blender still might start smoking. If the blender is running for more than a minute on a low power speed, it's likely the motor overheating. Let the blender cool down.
The blade assembly is made of two parts typically: blades and bearings. By blending hard objects, blades will dull and cause the motor to work harder and overheat. Blades last an average of 6 months with moderately heavy use. Sharpen or replace the blades if they are dull.
The bearing inside the assembly may also fail from overuse and misuse. Some blenders, like the Vitamix, are intended for running at their max speed in order for the cooling fans to properly work. In some cases, the bearing seal may melt or otherwise disintegrate. Water will then infiltrate the bearings during cleaning and wash away grease and cause rust to form. Replace the bearings or entire blade assembly if the blade won't spin.