Average life span: 10 to 20 years
What to do: Check for leaks around the system and with hose connections. You should also change your filter monthly.
Inspect and cleaned: Seasonally.

Average life span: Washer: 12 years; dryer: 14 years
What to do: Clean the dryer's lint filter and hoses. Kinks or ridges can cause highly flammable lint to build up, a major cause of fire.
Inspected and cleaned: Replace your washer hoses every 3 to 5 years.

Average life span: 14 years
What to do: Locate the condenser coils by checking your owner's manual. Clean them by unplugging the fridge and removing dust gently with a broom or brush. Check the seals by sliding a piece of paper in the closed door. If it falls out, you need to replace your seals. And defrosting regularly can't hurt.
Inspected and cleaned: Have it done if your at-home remedies don't work or if there are noises you can't locate.

Average life span: 13 years
What to do: Keep anything stringy, like pumpkin pulp, out of it. Also leave out tough produce, anything hard that can dull the blades, and grease, which can clog your pipes.
Inspected and cleaned: Have this looked at whenever your plumbing is checked.

Average life span: 5 to 8 years
What to do: Microwaves are simple appliances; they don't know the difference between the food you want cooked and old splatters in the chamber, so keep it clean and don't exceed the recommended usage.
Inspected and cleaned: Any time there's an issue. You should never attempt to work on it yourself.

Average life span: 9 to 12 years
What to do: Be mindful of what you put in it. Leave out small pieces that can get lodged in the drain and make sure everything is dishwasher-safe. Use a powdered detergent, because gels can cloud dispenser and glasses. Spend the few dollars on a rinse aid, such as Jet-Dry, every month or so.
Inspected and cleaned: Every 2 to 3 years.

Average life span: electric: 16 years; gas: 19 years
What to do: Check temperature with a thermometer or by following a basic white cake mix and making sure it cooks correctly. Keep it clean inside and out, using nonabrasive cleaners. Check your seals and the hinges, which can bend over time and let heat escape.
Inspected and cleaned: Any time it's not heating properly.

Average life span: electric: 6 to 14 years; gas: 5 to 9 years
What to do: Check your hoses, fittings and release valves. Also watch for damaged areas on the outside of the tank and leaking.
Inspected and cleaned: Every couple of years.