Even though your dishwasher's job is to clean, it too needs a once-over periodically. Over time, food residues gunk up the drain and spray arms. The clogs reduce the amount of water circulating during the wash and rinse cycles and dishes can end up with a film of baked-on food and soap. Plus, if you have unfiltered well water, mineral deposits build up and further reduce water flow. Here's how to keep your dishwasher-and dishes-sparkling.

1. Clean the drain: Locate the drain on the bottom of the basin (sometimes it's hiding below the spray arm). Use a paper towel or rubber gloves and remove any food-it can be pretty funky! If there's a removable screen around the drain, take that out too and rinse it off.

2. Wash away buildup: Run a hot-water cycle in an empty dishwasher with either 1 cup distilled vinegar in an open container on the top rack, 1/2 cup citric acid crystals in the detergent reservoir (look for it with canning supplies) or 1 cycle's worth of a dishwasher cleaner (look for one near detergents). They all work to dissolve food and mineral buildup in the spray arms and drain. You might need to repeat several times if the dishwasher's never been cleaned.

3. Wipe the rubber seal: The rubber gasket around the door can also get pretty gunked up and may have mold or mildew. Wipe it clean with a hot, soapy cloth. (Skip bleach, especially if you have a stainless interior-it's too corrosive.)

If you run a load every day, aim to clean your dishwasher monthly. And check the manual for more specific maintenance tips. (Ahem, I'm sure you still have it around.)