To clean a microwave, heat a bowl of water in it for a few minutes so the steam softens everything stuck to the walls, then wipe the inside down with dish soap and a damp cloth and dry it. If the burnt smell is still there afterward, the smell isn't in the air, it's in something you haven't cleaned yet: the splatter cover on the inside wall, the turntable and its ring, or the grease filter underneath an over-the-range unit. Manufacturers including KitchenAid, Whirlpool, and Maytag all publish the steam-and-wipe method. None of them tell you where the smell hides when that doesn't work.
This piece belongs to the kitchen deep-clean order on House Tweaks, which is worth reading first if the whole kitchen needs work rather than just the microwave.
Start here: the steam method
This is the part every manufacturer agrees on, and it works, so there's no reason to reinvent it.
- Take out the turntable and the roller ring underneath it.
- Scrape or lift out any loose burnt debris. If something is charred and solid, get it out before you add moisture, or you'll just smear it.
- Put a cup of water in a microwave-safe bowl. Adding a tablespoon or so of white vinegar or lemon juice helps with odor, and both are recommended by manufacturer guidance. Plain water works for the softening part.
- Heat it for a few minutes, until the inside is steamy. Whirlpool's own guidance runs in the three-to-five minute range; watch it rather than walking away, and don't let the bowl boil dry.
- Leave the door shut for a few more minutes so the steam does the work.
- Open it, take the bowl out (use a mitt, it will be hot), and wipe the ceiling, walls, floor, and the inside of the door with a soft cloth and a little dish soap.
- Rinse the cloth and go over everything again with plain water, then dry it.
That rinse pass matters. The inside of a microwave is a food surface. Dish soap residue left on the walls will smell when it next heats up, which is exactly the problem you're trying to solve.
Two things not to do. Don't run the microwave empty, and don't spray cleaner directly into the vents or through the grille. Liquid getting into the electronics is how a cleaning job becomes a repair.
Wash the turntable and the ring separately
The glass plate can be washed in the sink like a dish, or in the dishwasher if the manual allows it. The roller ring underneath is the part people forget. It sits in a shallow recess that collects everything that drips off the plate, and that recess bakes every time you run the machine. Lift the ring out, wash it, and wipe the recess it sits in.
If your burnt smell survived the steam clean, this is one of the two places it usually lives.
The other place the smell lives: the splatter cover
Look at the inside wall or ceiling of your microwave and you'll usually find a small flat panel, often a light beige or gray square, that isn't part of the metal cabinet. That's the cover over the waveguide, the channel that carries microwaves into the cavity. It's there to keep food splatter out of the works.
It catches splatter, and splatter burns onto it. Because it's flat, light-colored, and slightly recessed, most people wipe right past it. A cover with carbonized food baked onto it will keep producing a burnt smell every time the machine runs, no matter how clean the walls are.
Wipe it gently with a damp soapy cloth and dry it. Do not scrub it hard, do not soak it, and do not remove it. If it's cracked, charred through, or arcing (you would have seen sparks), stop using the microwave and check your manual, because that cover is a replaceable service part on many models and running the machine without a sound one is not something to improvise around.
If it's an over-the-range microwave, clean the filter
A microwave mounted above a cooktop is also your range hood, and it has a metal mesh grease filter in the underside. That filter has been catching cooking grease for as long as anyone has owned the appliance, and hot grease smells burnt.
The filter slides or clips out from the bottom. Degreasing it is the same job as cleaning a range hood filter, and that piece covers the method properly. If the smell in your kitchen is "burnt" rather than "burnt popcorn," this filter is a strong suspect, and cleaning it fixes a ventilation problem at the same time.
Some over-the-range models that recirculate rather than vent outside also have a charcoal odor filter behind the top grille. Charcoal filters are not cleanable. They're consumable and get replaced, and your manual will say how often. If yours has never been changed, that alone can carry an old burnt smell indefinitely.
Absorbing what's left
Once everything is physically clean and dry, and there's still a faint smell, an absorber helps. Leave an open container of baking soda or a cup of dry coffee grounds inside with the door closed overnight, then remove it. Both are widely recommended by manufacturers and both work on the same principle: something porous sitting in still air pulls odor molecules out of it.
Leaving the door open for a few hours also does more than people expect, because a sealed cavity holds smell and a ventilated one doesn't. If the burn was bad enough to smoke, open a window and run your range hood or an exhaust fan, because by then the smell is in the room, not only in the appliance.
The honest limit: what won't come out
Some burnt smells don't fully leave, and it's better to know that than to keep scrubbing.
If food burned badly enough to scorch the plastic or paint of the cavity itself, the damaged material is now part of the smell. Cleaning removes residue. It doesn't reverse heat damage to a surface. The same is true if smoke got into the vent path and the internal fan housing, which is not a user-serviceable area, and not somewhere you should be spraying anything.
In those cases the smell fades over weeks of use and airing rather than disappearing in an afternoon. And if you're weighing whether a badly scorched microwave is worth keeping at all, that's a triage question rather than a cleaning one: our guide to deciding between a repair and a replacement walks through how to think about it.
One more line worth stating because these products live under the same sink: never mix bleach with vinegar or with ammonia. Both combinations produce toxic gas. Bleach has no place inside a microwave anyway, since it's a food surface, but the warning is worth repeating wherever a cleaning article mentions vinegar.
Keeping it from happening again
Cover food. A plate or a vented microwave cover stops the splatter that becomes next month's burnt smell. Wipe spills the same day rather than heating them again. Check the turntable recess every time you wash the plate, since you already have it out.
And if the microwave sits above the stove, put the grease filter on the same schedule as the rest of your kitchen cleaning routine rather than waiting until it smells.
FAQ
Why does my microwave still smell burnt after I cleaned it? Because the smell usually isn't on the walls. Check the splatter cover on the inside wall or ceiling, the recess under the turntable ring, and, if it's an over-the-range model, the grease filter underneath and any charcoal filter behind the top grille.
Can I use vinegar to clean a microwave? Yes. Heating water with a tablespoon of white vinegar or lemon juice is a method manufacturers themselves publish. Rinse the interior with plain water afterward, since it's a food surface. Never combine vinegar with bleach.
Is it safe to run a microwave with a burnt smell? A smell alone is a cleaning problem. Sparking, arcing, a scorched or cracked splatter cover, or a burning smell with nothing in the machine are different, and mean you should stop using it and get it looked at rather than cleaning around it.
How do I get burnt popcorn smell out? Same sequence: steam, wipe with soap, rinse, dry, then leave baking soda or dry coffee grounds inside overnight. Burnt popcorn is a strong odor and often needs two or three nights of absorbing plus an open door in between.
Can I clean the microwave's charcoal filter instead of replacing it? No. Charcoal odor filters in recirculating over-the-range microwaves are consumable parts, not washable ones. Washing one doesn't restore it. Your manual will give the replacement interval and the part number.
Nothing here is a claim to have tested every microwave on the market. It's what the manufacturers publish, plus the parts of the job they leave out. More on how this site works is on the about page.
