Dishwashers deal with food scraps, hard water and heat nearly every day, and over time that takes a toll. Clogged filters, failing drain pumps, worn spray arms, faulty door latches and leaking door gaskets are some of the issues technicians see most.

Early warning signs include standing water in the bottom after a cycle, gritty residue or cloudy film on dishes, a cycle that stops partway through, or water seeping out under the door. A dirty filter is often something you can clean yourself in a few minutes. A failed pump, heating element or control board generally calls for a professional, and costs vary widely by model and region.

Scrape plates before loading, clean the filter regularly and run the kitchen tap until the water is hot before starting a cycle. If you notice a leak, turn off the dishwasher and look for the source quickly, because slow leaks under cabinets can damage flooring and subfloors long before anyone notices.