You never want to smell smoke coming from one of your appliances. You probably know to pull a bag of popcorn out of the microwave if it smells like it's burning. If it is your dryer that has the burning smell, then it's time to perform maintenance on the unit.
The burning smell coming from your dryer occurs when the unit is running. It will be most noticeable when you dry clothes on the high heat setting. The odour of smoke can permeate the laundry inside the dryer. It can also make your entire laundry area smell bad. While the smoke smell can be alarming, it does not mean anything in the dryer is on fire.
The most common cause of a burning or smoke smell from a dryer is lint built up inside the unit. When lint isn't removed from a dryer's lint trap after every use, it builds up inside, often within the dryer door. As more lint is packed into the door with every load run, the lint gets hotter every time you run the dryer. Hot lint emits a smoky smell, like it is burning even though it has not caught fire.
Getting the lint out of your dryer will stop the burning smell. Pull all the lint out of the trap. Next, get it out of the door. If you can't reach it with your fingers, you can pull it free with a straightened wire hanger. If the angle on your dryer prevents you from using the hanger, look for a flexible wand. Available for purchase at home improvement stores, the soft wand attracts lint and pulls it out of your dryer.
Just because the smell of burning in your dryer isn't a fire doesn't mean you can ignore it. Lint can catch fire. Cleaning the lint trap after every load you run in your dryer will prevent the problem from returning. If the odour of smoke lingers in your dryer, combine 1 part white vinegar with 1 part water. Using a sponge, damp mop out the dryer's interior, then leave the unit's door open so it can dry.