If your dishwasher smells unpleasant, the cause is usually trapped food debris, clogged filters, or stagnant water rather than a plumbing system problem.
Dishwashers operate in warm, moist conditions, which can allow bacteria and residue to build up over time.
The Most Common Reasons This Happens
1. Dirty Filter
Most dishwashers have a removable filter at the bottom. If food particles collect there, they can begin to smell.
This is one of the most common causes.
2. Blocked Spray Arms
Food debris can clog the spray arm holes, reducing cleaning efficiency and allowing residue to accumulate.
If dishes are also not coming out clean, see:
→ Why Is My Dishwasher Not Cleaning Properly?
3. Standing Water in the Base
If water is not draining fully after each cycle, it can become stagnant and cause odours.
If you notice water remaining inside, see:
→ Why Is My Dishwasher Not Draining?
4. Grease and Detergent Buildup
Over time, grease and detergent residue can collect inside the machine, especially on the door seal.
5. Drain Hose Issue
If the drain hose is incorrectly installed or partially blocked, wastewater may not exit properly.
If other drains in your home smell, see:
Is This Normal?
It may be minor if:
- The filter hasn’t been cleaned recently
- The smell improves after a hot wash
- The issue developed gradually
It may require attention if:
- The smell is strong and persistent
- Water remains at the bottom
- Cleaning performance has declined
What You Can Do
If your dishwasher smells bad, you can:
- Remove and clean the filter
- Wipe the door seal
- Run a hot maintenance cycle
- Check for standing water
If odours persist despite cleaning, further inspection may be necessary.
For more related issues, see:
→ Dishwasher Problems Explained
→ Appliance Problems Explained