Why your dishwasher smells (and how to fix it in 10 minutes)
A smelly dishwasher almost always comes down to one of three things. Here's how to find which one, and a 10-minute fix you can do tonight.
By Wenest
If you opened the dishwasher this morning and it smelled like a forgotten lunchbox — you're in good company. It's one of the three most common "is this thing broken?" calls we get, and almost always it isn't.
Three things cause a smelly dishwasher. You probably have one of them. Let's find out which.
1. The filter (most likely)
Modern dishwashers have a removable filter at the bottom of the machine, under the lower spray arm. Its job is to catch food that didn't fully break down.
Nobody cleans it. We've pulled filters out of three-year-old machines that had never been touched. The smell was something we will not describe in print.
To clean it:
- Pull out the lower rack.
- Twist the filter cap anti-clockwise (it's usually marked with arrows). Lift it out.
- Rinse under hot water with a small brush — an old toothbrush works.
- Use a drop of dish soap if needed.
- Twist back in until it's snug.
This alone solves the smell about 70% of the time.
2. The door seal
That rubber gasket around the door is a perfect trap for splash-back: tomato sauce, coffee, mince. It also never gets cleaned.
Open the door fully, get a damp cloth with a tiny bit of dish soap, and run it all the way around the rubber. Get into the folds — that's where the gunk is.
Two minutes. You'll see what comes off.
3. The drain hose or air gap
If you've cleaned the filter, wiped the seal, and the smell is still there — the issue is downstream. Either the drain hose has a sag holding stagnant water, or the air gap (a small chrome cylinder on the bench next to your kitchen tap, if your kitchen has one) is blocked.
This one usually does need a plumber or appliance tech, especially if you can also smell it from the sink.
The 10-minute reset
Once a quarter, do this:
- Empty the dishwasher.
- Pull and rinse the filter.
- Wipe the door seal.
- Put a cup of white vinegar (or a dishwasher cleaner tablet) on the top rack.
- Run a hot cycle, empty.
That's it. The first time you do it after years of neglect, the difference is dramatic. Your glassware stops coming out with that faint film. The kitchen stops smelling vaguely off when you open the cupboard next to it.
What we tell our members
Dishwasher maintenance is on the same six-monthly list as smoke alarm batteries and air-con filter changes. It's small enough to forget and annoying enough to matter.
If you've never thought about it before, today is the day. Ten minutes after dinner. The smell will be gone before you finish loading tomorrow's breakfast plates.
When it's actually broken
A few signs it's not just maintenance:
- Water pooling at the bottom after a cycle (drain pump issue).
- Burning smell during the cycle (motor or heating element).
- Dishes coming out gritty (spray arm clogged or pump weak).
These need a tech. The first two are also worth turning the machine off at the wall while you wait, just in case.
For everything else — it's the filter. It's almost always the filter.
Frequently asked
- Hot cycles don't reach the filter or the door seal — the two places food residue actually sits. A clean cycle won't fix what's stuck under the spray arm or in the rubber gasket.
