KitchenAid mixer smells like burning: causes and what to do

Common causes

• Overloading. Heavy dough or a batch that is too big makes the motor work hard and heat up.
• Worn carbon brushes. They carry power to the motor and wear down over time. When they get too short they can spark and give off a burning smell, mostly on older machines.
• Old or degraded grease. Grease that has broken down stops protecting the gears, which creates heat and friction. A re-grease puts that right.
• Worn or stripped gears, which often grind as well.
• A mixer stuck at full speed. Running flat out heats everything quickly, and it points to a failed speed controller.
• A beater set too close to the bowl. See the dime test guide.

What to do right now

1. Stop mixing and unplug the mixer.
2. Let it cool completely before you use it again.
3. Next time, make a smaller batch or split a dense dough into two.
4. Check that the bowl is seated properly and the beater is not scraping the bowl.

When to get it checked

The diagnostic is the quick way to find out. I open the mixer up, find the actual fault and quote the repair. If it is not worth fixing I will say so, and the diagnostic fee comes off any repair you go ahead with.

• The smell comes back even with a light load
• The mixer slows, stalls or cuts out
• You hear grinding (see grinding noise)
• You see sparks, or the housing gets very hot

How to avoid it

Stay within the capacity in your mixer's manual, split dense doughs into smaller batches, never knead above speed 2, and let the mixer cool between heavy jobs. Keeping the gearcase properly greased helps too, which is what a re-grease is for.