Any drain in your house requires a water trap to prevent sewer gases from entering the home. Dishwashers don’t have an internal water trap, so they must use an external P trap. The most convenient P trap for the dishwasher is already in the plumbing under your sink.

Yes, vinegar is an excellent homemade solution to clean a dishwasher. Its acidity will cut through any buildup, while its natural deodorizing capabilities will take care of any nasty smells. 

The most common reason for a smelly dishwasher is a dirty dishwasher filter. The filter is responsible for catching food while your machine is running to prevent clogs. Over time, that filter gets more and more filled with food particles. Cleaning your dishwasher filter monthly can keep the smell at bay.

When deciding whether to repair or replace your dishwasher, consider its age, the repair cost, and its warranty status. It is often worth repairing a dishwasher if it is only a few years old, the problem is minor, or the appliance is still under warranty. A common guideline is the 50% rule: if the repair cost is less than 50% of the price of a new unit, a repair is generally recommended. However, if the dishwasher is more than 10 years old or requires frequent repairs, replacement is likely the more cost-effective choice to avoid future issues. For context, a new dishwasher costs between $1,000 and $1,500 on average, while typical repairs cost several hundred dollars. Simple fixes like a damaged gasket or clogged filter can be inexpensive, but major repairs like a new pump or motor can be costly.