Give your household equipment a little workout now and then, to make sure anything mechanical will perform well when needed. Periodic exercise can extend the usable life of many items.
About once a year, move down the row of circuit breakers in your household electrical panel, switching each one off and then back on. This breaks apart any corrosion that might have built up on the contacts (and excess corrosion can prevent a circuit breaker from properly shutting off the power if there's ever a dangerous overload). Afterwards, remember to reset any digital clocks that lost power when the breaker on their circuit was flipped.
Also about once a year, locate the water shut-off valves throughout your house (under sinks, behind showers, on main water lines). Gently close each valve and then open it again. This reminds you where they are located and ensures that they will work if you ever need them in a hurry. However, if your plumbing is more than 50 years old and the valves haven't been used in a long time, don't do this yourself. Hire a plumber to check the valves for you and replace them if needed (typically about $75-$200).
Once a month or every other month, go around the house and turn on and off any neglected appliances or fixtures. This could include the plumbing in a rarely used attic or basement bathroom (turn on the taps, flush the toilet), a garbage disposal that almost never gets used, or a Jacuzzi pump that doesn't see much action. Exercising them keeps things from freezing up when a guest or a prospective homebuyer tries out something you never use.
Test the garage door opener on a monthly basis, to make sure it reverses itself when there's an obstruction. The U.S. Consumer Product Safety Division recommends placing a 2"x4" board on the floor in the path of the garage door. If the door doesn't automatically reverse when it hits the 2x4, have the opening mechanism adjusted, repaired or replaced, as needed.
Moving the Fridge
Okay, so this one is exercising you and not the appliance, but at least once a year pull the refrigerator away from the wall and use a vacuum or brush to clean the coils on the bottom or back. They conduct hot air out of the unit, and if they're coated with dust they are less efficient, and make the refrigerator work harder. While you're at it, also vacuum the exhaust duct on the clothes dryer, to remove excess lint.
Draining the Tank
If you have a traditional, tank-style water heater, sediment builds up in the bottom of the tank. There should be spigot near the bottom -- at least once a year, use that spigot to drain the water heater, and then clean the sediment off the floor of the tank. This should help the water heater operate more efficiently and last longer.
Testing the Detectors
Maybe most people already know that they should test their smoke and carbon monoxide alarms twice a year, but how many actually do it? Hit the "test" button on each device, to make sure it's working properly. (Many homeowners choose to do this when they're changing their clocks for daylight savings, in the spring and fall.) And once a year, replace all batteries. Even smoke detectors that are hard-wired into the household electrical system have back-up batteries that should be checked and replaced as needed.
These simple steps are either free or relatively low cost, but they can make a big difference in the operation and durability of key household devices. And if put your mechanical equipment through these "exercises," you can be confident that everything will work when you need it.