A dishwasher that smells nearly always has food, water or a slimy film sitting somewhere the wash doesn't reach, and that's where I'd look first. My checklist is the filter, the sump under it, the rubber door gasket, and any drain hose that allows dirty sink water to run back in. A dishwasher is a warm, wet, closed box, so anything left in it for a few days goes off.
A dishwasher filter is the mesh cup and screen in the floor of the tub that catches food before the pump sends water back up to the spray arms. It's the first thing to check on most machines, and the kind of smell tells you where to look after that.
I'm Michael Ruhr, co-owner of Merit Home Furniture on Vancouver Island. I work out of our Duncan store. Merit's dishwashers, sold alongside our ranges, fridges and laundry appliances, are listed at our Campbell River and Port Alberni stores, or come as special orders. The fixes below come from Bosch, KitchenAid, Whirlpool, Frigidaire and Samsung's own help pages.
Why does my dishwasher smell? Match the smell to its source
Each dishwasher smell points to a different part of the machine or the plumbing behind it.
| Smell | Usual source | First check |
|---|---|---|
| Sour or rotting food | Filter, sump, front of the tub floor | Pull the filter and rinse it |
| Musty or wet dog | Film on the door gasket, a tub left shut and damp | Wipe the gasket, leave the door ajar |
| Sewage or rotten eggs | Sink drain, garbage disposal, a drain hose with no high loop | Run the disposal, check the loop height |
| Burning plastic | Plastic resting on the heating element | Stop the cycle, cut the power, let it cool |
| Plastic, hot tar or varnish in a new machine | New tub, sound-deadening coating, motor | Keep using it; the makers say it fades |
When two smells overlap, do the filter first. It's free and it rules out the most common cause.
Why does my dishwasher smell sour? Food in the filter and tub
Food caught in the dishwasher filter is the cause Bosch names first: every cycle leaves scraps there. Whirlpool adds the spray arms and the bottom of the tub, and asks for the filter to be cleaned at least once a month. KitchenAid points to the front of the tub floor, where it says soils pile up, and to the door gaskets. Those are the places odours lurk, and the makers' pages add up to this routine:
- Let it cool and switch it off. Then lift out the racks that are in the way.
- Take out the filter. The manual shows how. On Frigidaire's Canadian page, the cylinder fine filter turns counterclockwise, and the coarse filter lifts out after it.
- Scrub it. Bosch says running water, soap and a soft brush; Frigidaire suggests a bottle brush for stuck food.
- Clear the spray arms. Bosch's test is to run water through them and free any blocked hole with a toothpick.
- Wipe the tub floor and gasket with a sponge and warm water, as KitchenAid suggests, then seat the filter firmly.
Two KitchenAid models listed for our two appliance stores carry what KitchenAid calls True Self-Cleaning Filtration, which it says removes the need for manual filter cleaning. One is the KitchenAid 24 in. top control with 360 Max Jets, priced online at $1,399.99 to $1,499.99 before applicable taxes.
A machine that sits unused builds smells too, at a summer cabin or during a month away. KitchenAid suggests a rinse cycle on a partial load when it isn't run daily, so scraps don't rot while it fills.
Standing water, the drain hose high loop and the air gap
Standing water in a dishwasher goes stale fast. Whirlpool lists it beside trapped food as a main source of odour, and blames drainage problems or a blocked filter, so a clean filter often fixes both.
KitchenAid's help page says the drain hose should rise in a high loop at least 20 inches from the floor before it drops to the sink drain or disposal. The loop stops dirty sink water running back into the dishwasher or being siphoned in. Below 20 inches, KitchenAid says to use an air gap.
An air gap is the small cap some kitchens have on the counter beside the tap. Frigidaire's Canadian page says to lift its cover and check it's clean, and notes it isn't part of the dishwasher or its warranty. Local plumbing rules decide which of the two a house needs, and a licensed plumber will know. A dishwasher that won't drain at all is a bigger job, and Merit is writing a separate guide for it.
How do I clean a smelly dishwasher drain hose?
A smelly drain hose gets cleaned from inside first: clear the filter, then put a dishwasher cleaner through an empty hot cycle. Whirlpool says its affresh cleaner reaches the pump, valves, drain and recirculation hoses. Under the sink, check the hose for kinks or a dip where water sits. Taking the hose off is plumbing work, with the water and power off first.
Why does my dishwasher smell like sewage or rotten eggs?
A dishwasher that smells like sewage usually shares its drain with the kitchen sink, and the smell comes from that side. Samsung's Canadian page says lingering odours may come from the sink drain or garbage disposal, and to clean those or call a plumber. KitchenAid says to run the disposal to clear debris, then clean the disposal and dishwasher. Without a high loop, that dirty water can flow back into the tub, so the loop height above matters here too.
Why does my dishwasher smell like wet dog?
A wet-dog or musty dishwasher smell is usually damp rather than food. It's film on the rubber door gasket and the bottom lip of the door, in a tub kept shut between loads. Whirlpool says to wipe the seals with a damp cloth and mild detergent. Samsung's Canadian page says to leave the door slightly open after use so moisture escapes.
A 2011 study in Fungal Biology sampled 189 dishwashers in private homes and found fungi in 62% of them. The authors linked that to the heat, moisture and alkaline conditions inside. The study didn't measure smells, so it doesn't prove fungi cause the wet-dog odour. It does note the two black yeasts found most often can settle in the lungs of people with cystic fibrosis. Anyone with a lung condition and concerns should ask their doctor.
Some newer dishwashers open the door themselves when the cycle ends. These are the Merit listings that say so, priced online before applicable taxes:
| Dishwasher | Door feature, price, store |
|---|---|
| KitchenAid 24 in. front control, 47 dBA | Opens 4 inches after the dry cycle; $1,099.99; Campbell River and Port Alberni |
| Samsung 24 in. with AI Wash | Opens on its own to let steam out; $1,249.99 to $1,299.99; Campbell River |
| LG 24 in. FlushFit front control | AutoVent Dry opens it slightly; $699.99; Campbell River |
| Frigidaire 24 in. third rack, smudge-proof | Eco Air Dry props it open; $699.00; Port Alberni |
None of these listings claims the feature stops smells; the makers sell it as a drying aid. A tub that dries between loads is still what Samsung's advice is after.
Why does my dishwasher smell like burning plastic?
A burning-plastic smell usually means something plastic dropped through the racks onto the heating element in the tub floor. KitchenAid says to let the machine cool for at least 30 minutes, then lift off any plastic or food with something that isn't metal, such as a wooden spoon. Traces left behind burn off over a few cycles, it says, and a rinse or cleaning cycle helps with the smell. To stop a repeat, it says to wash only dishwasher-safe plastics, on the upper rack.
An electrical smell is a safety call. If it smells sharp and electrical rather than plasticky, or there's smoke, stop the cycle and switch the dishwasher off at its breaker or plug. Leave it off until a qualified technician has checked it, and call 9-1-1 if there are flames.
In 2017, Technical Safety BC passed on a Health Canada recall of 61,000 dishwashers from Bosch, Thermador, Gaggenau, Kenmore and Jenn-Air whose power cords may overheat. They were sold between January 2013 and May 2015, and owners were told to stop using them immediately. The model and serial numbers sit on the inner door's top edge or the right side panel.
Why does my new dishwasher smell?
A new dishwasher smell is normal for a while, say Whirlpool and KitchenAid, and each one has its own timeline:
| New-machine smell | Source and how long |
|---|---|
| Plastic | The new tub and parts; about two weeks |
| Hot tar or petroleum | Black sound-deadening coating outside the tub; 4 to 6 weeks |
| Varnish | Varnish on the motor windings; about a month |
KitchenAid says the tar-smelling coating is on most stainless steel tub dishwashers. Of the 53 dishwashers listed for Merit's Campbell River and Port Alberni stores, 41 list a stainless steel tub, 5 a plastic tub and 2 a hybrid one. For the plastic smell, KitchenAid suggests a vinegar rinse with an air dry and no detergent. A new machine that smells of sewage points to the drain hookup instead, and any smell that outlasts those windows goes to the store you bought from.
Cleaning a smelly dishwasher: what each maker recommends
Cleaning a smelly dishwasher starts with the filter, and then each maker suggests a cycle in an empty machine:
| Maker | Cleaning advice and how often |
|---|---|
| Whirlpool | Filter at least once a month; a dishwasher cleaner in an empty hot cycle, ideally monthly |
| KitchenAid | 2 cups (500 mL) of white vinegar in an upright glass on the lower rack, no detergent, dry off; or affresh every 30 days |
| Bosch | Its cleaner a few times a year on the hottest, longest cycle; its descaler the same way for hard water |
| Samsung Canada | An empty cycle with a chlorine-based detergent, white vinegar or a cleaning tablet |
| Frigidaire Canada | Rinse the glass trap and filters; check the counter air gap if there is one |
Samsung's Canadian page also says a dishwasher needs hot water, 120 to 149 degrees Fahrenheit, about 49 to 65 Celsius. It suggests running the sink hot first, and checking the water heater if it's slow. A full deep clean and the right way to load are each getting a separate Merit guide.
Can I use bleach to clean my dishwasher?
Bleach is out for any dishwasher with a stainless steel tub, by Samsung's account, and 41 of the 53 on our listings have one. Mixing is the bigger danger. Health Canada warns that bleach reacts with any cleaner containing ammonia or an acid, including vinegar, and gives off toxic gases. Never put bleach and vinegar in the same cycle, and keep chlorine detergent and vinegar runs apart.
Can I put baking soda or a drop of Dawn in my dishwasher?
Baking soda isn't in the maker help pages I read for this guide; they name vinegar or a dishwasher cleaner. Dawn is a firm no. KitchenAid says hand dish soap makes excess suds in a dishwasher, and only automatic dishwasher detergent belongs in it.
Why does my dishwasher smell even after cleaning? When to call a technician
A dishwasher smell that comes back within days of a full clean is past what cleaning can fix. Samsung's Canadian page says poor draining or error codes can point to an underlying issue, and a machine that works but still smells may need professional service. I'd stop cleaning and call someone in these cases:
- Water sits in the bottom after every cycle, even with a clean filter.
- The smell is electrical, or the breaker trips.
- Sewage smells return after the sink and disposal are clear, which is a plumber's job.
- A new machine still smells past the makers' windows.
Some makers void the warranty if anyone but their authorized servicers does the repair, as our guide to what each maker's warranty covers explains for Danby. For a dishwasher bought from Merit, the store you bought from is the first call, and Merit's own warranty and repair terms are on one page. That follow-up is part of what an Island store does after the sale. I can't diagnose a dishwasher from a description, and nothing here stands in for a technician who can see it.
If my own dishwasher started to smell, I'd pull the filter before buying any cleaner. And I'd get into the habit of leaving the door open a crack overnight, which costs nothing.
Where the dishwasher smell advice comes from
- Bosch, Dishwasher Troubleshooting: Dishwasher smells, checked November 2026.
- Whirlpool Product Help, Removing Odors in your Dishwasher, checked November 2026.
- KitchenAid Product Help, Checking the Drain Loop Height, checked November 2026.
- KitchenAid Product Help, Melted Plastic or Charred Food Odor, checked November 2026.
- KitchenAid Product Help, Hot tar or Petroleum Like Odor, checked November 2026.
- KitchenAid Product Help, Plastic Tub Odor, checked November 2026.
- KitchenAid Product Help, Food Odors, checked November 2026.
- KitchenAid Product Help, Cleaning the Dishwasher, checked November 2026.
- KitchenAid Product Help, Odor From Garbage Disposal, checked November 2026.
- KitchenAid Product Help, Removing Suds, Bubbles or Soap Foam, checked November 2026.
- Frigidaire Canada, Dishwasher Glass Trap and Filter Guide, checked November 2026.
- Samsung Canada, Samsung dishwasher care for removing and preventing unwanted odors, checked November 2026.
- Zalar P and others, Dishwashers, a man-made ecological niche accommodating human opportunistic fungal pathogens, Fungal Biology 115(10):997-1007 (2011), abstract checked November 2026.
- Technical Safety BC, 61,000 dishwashers recalled due to fire risk, checked November 2026.
- Health Canada, Expanded Recall: BSH Home Appliances Corporation recalls Various Dishwashers Due to Fire Hazard (2017), checked November 2026.
- Health Canada, Reduce your risk from toxic gases: Never mix bleach with other cleaning products, checked November 2026.
- Merit Home Furniture's 53 dishwasher listings for the Campbell River and Port Alberni stores, with tub materials, drying features and prices, read November 1, 2026.
Replacing a dishwasher on the Island: Campbell River and Port Alberni
Merit's dishwashers are listed at our Campbell River and Port Alberni stores, so that's where I point anyone ready to replace a smelly machine. A call first saves a wasted drive: ask which models are set up to open and look inside. Bring the width of the opening under the counter, and note whether your sink has an air gap or a disposal.
- Merit Campbell River: 1300 A Homewood Rd, (250) 286-0868
- Merit Port Alberni: 2935 Third Ave, (250) 724-6644
Call Campbell River about dishwashers, (250) 286-0868
Call Port Alberni about dishwashers, (250) 724-6644
Getting the new one home and hooked up is worth raising on that call, and how Merit delivery and setup works is written up too. Models with no store listed are special orders, on the line (250) 746-5527, and how deposits and exchanges work at Merit has its own page. Every model sits in a single list of Merit's dishwashers, with the under-counter built-in models on a list of their own. Merit's other guides to kitchen appliances are gathered on one page.