Your dishwasher drains through a hose that attaches to the plumbing below your sink or snakes out the back of your machine. In most cases, you can access one side of the hose from below your sink, as it usually ties into the same drainline that your sink uses. Otherwise, you may need to pull the dishwasher out of the counter to access it.

Yes, a dishwasher needs an air gap to prevent backflow. Additionally, in many locations, air gaps or another measure to prevent backflow are required for building code compliance. There are alternatives to an air gap, like a Studor vent or a loop and trap design, but an air gap is the simplest and most popular solution.  

To create a siphon break and remove any chance of dirty sink water or water that backs up into the sink from getting into your dishwasher, your dishwasher drain hose needs to have a high loop or an air gap device as part of its installation. All building codes require at least a high loop. In many places, it’s necessary to install an air gap device to meet the code.

You should deep-clean your dishwasher every month for optimal performance. A simple scrub down using a homemade vinegar liquid solution is all you need, but don’t use cleaners that aren’t for dishwashers. 

If your dishwasher needs repair, expect to spend between $50 and $100 or $100 to $200 per hour to hire a dishwasher repair technician to service your machine.

Treat hard water with water treatment tablets to keep your dishes from getting spotty in between washes. Drop one of these into your dishwasher monthly and run a basic cycle with the machine empty.