A Bosch 300 Series SHS43CF5N dishwasher that smells, with a musty, sour or sewer odor from the tub when you open the door, is holding food, grease or stale water, and the cure is cleaning and drainage checks. The most common cause is the filter at the bottom of the tub, which traps food scraps; if it is not cleaned, they rot. Twist out the cylindrical filter and the flat fine filter, rinse them under the tap, scrub them with a soft brush and refit them firmly.
The checks in more detail
Clean the sump below the filter of any debris. Check the spray arms for clogged holes, which you can clear with a toothpick, and wipe the door gasket and the edges of the tub with a damp cloth and a mild cleaner, where grease and food collect. Run a cleaning cycle with a dishwasher cleaner, or with a cup of white vinegar in a bowl on the top rack on a hot cycle, which is a common household method; do not mix vinegar with bleach.
Leave the door ajar after a cycle to let the tub dry, and run the dishwasher regularly, since a machine used rarely grows odors. Scrape plates, but do not pre-rinse to a spotless state if you use detergent that needs soil to work. Use the hot water setting, and run the tap until the water is hot before starting. If the smell is like drains, check the drainage. A drain hose without a high loop or an air gap can allow water and odor to flow back from the sink, and a garbage disposal with old food can send odor through the connection.
Run the disposal with water and clean it. A kinked hose leaves stale water in the tub, so check it. Check under the sink for a slow leak or a damp cabinet, since moisture breeds smells. If the odor persists after cleaning, the filter, the drain and the air gap are the places to look, and a technician can check the pump housing. Keep the model number for Bosch support and run the monthly cleaning habit.
Differential
Likely causes of “Bosch 300 Series SHS43CF5N dishwasher smells bad or musty”, and how to tell them apart
- 1
A dirty filter and sump
What separates it A rotting smell
How to confirm Clean the filters and the sump
- 2
Grease in the gasket and tub edges
What separates it A sour smell
How to confirm Wipe with a mild cleaner
- 3
Clogged spray arm holes
What separates it Food trapped
How to confirm Clear them with a toothpick
- 4
Poor drainage or no high loop
What separates it A sewer smell
How to confirm Check the hose loop and air gap
- 5
Infrequent use
What separates it Stale water
How to confirm Run the dishwasher regularly and leave the door ajar
Before you touch a setting
Record this first — changing settings destroys the evidence
- Where the smell is strongest
- When the filter was last cleaned
- Whether the drain is clear
- How often it runs
Try in this order
0 of 6 completedRemove and clean the filters
ReversibleAnd the sump.
Wipe the gasket and tub edges
ReversibleWith a mild cleaner.
Clear the spray arm holes
ReversibleWith a toothpick.
Run a cleaning cycle
ReversibleWith cleaner or vinegar.
Check the drain hose loop
ReversibleAnd the disposal.
Leave the door ajar
ReversibleAfter use.
Model-specific
What is true of this model and not of its siblings
- Filter
- The first place to look.
- Door ajar
- Lets the tub dry.
Stop boundary
When this stops being a self-service repair
- !If the smell persists after cleaning and drainage checks, contact Bosch with the model number
- !Check for a leak under the sink
- !Run a monthly cleaning cycle
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why does my Bosch smell?+
Food in the filter or stale water.
How often should I clean the filter?+
At least monthly.
Can I use vinegar?+
On a hot cycle, never with bleach.
Could the drain cause it?+
Yes.