Make your heating and cooling systems last longer

Doing simple, regular maintenance on your heating and cooling systems will keep them reliable and extend their lives. And if that's not enough incentive to do these easy tasks, all the money you'll save should be!

• Oil-fired furnaces require more maintenance than gas-fired furnaces do.
• But whichever type you have, it will last longest and cost you the least to run if you have it checked annually by a professional — you can usually contract with your fuel supplier to automatically do the work each year.

Just like the furnace, the heat distribution system should be professionally serviced each year. There are three common heat delivery systems:

• Forced hot-air system: In addition to annual professional servicing, you should change the air filter each month during the heating system. Usually you'll find it just inside the furnace housing or in a slot between the furnace and the main duct. It's also a good idea to vacuum your registers before the start of each heating season.

• Hot-water system: If you have cast-iron radiators — "bleed" any air out of them before each heating season. This involves using a special key or a screwdriver to open a little valve at the top of the radiator. At first, hot air will come out of the valve. Close it when a steady stream of water comes out.

• Steam systems: These are found almost exclusively in older homes and use cast-iron radiators just like the ones in a hot-water system. They need to be bled the same way.

Hot-air ducts should be cleaned about every five years or whenever a dust-producing renovation is done.

• A layer of dust acts as a layer of insulation. If your radiators or the convection fins of your hot-water baseboard are dusty, your furnace will need to run longer and more often to force heat through them.
• Of course, this not only wears the furnace out sooner but also costs you more fuel as well. So save money by regularly vacuuming your radiators' baseboards.
• Be sure to take the covers off to get to the fins.

• Those thin metal convection fins under the covers of your hot-water baseboard are easily bent or crushed together. This greatly decreases their efficiency.
• Fortunately, they are just as easy to straighten when you take the covers off to vacuum.

• The key to making an air conditioner last is to keep air flowing through it as easily as possible.
• In the case of a window air conditioner, the air is pulled in through tiny fins at the back and pushed out through tiny fins in the front.
• Remove the unit from its case, and vacuum these fins with a soft brush attachment. If the rear fins are really dirty, you can rinse them out with a garden hose.
• You can access the fins of a central-air system's outdoor unit by removing the cover.
• Vacuum the fins from the outside, and rinse them with a garden hose, spraying from the inside.

• The filter at the front of a window air conditioner is easy to remove — usually you just pull it out.
• Do so every month or so, and rinse the filter in warm water with a squirt of dishwashing liquid.

• The outdoor unit on your central AC unit is designed to withstand the weather.
• Covering it could trap moisture and actually rust the unit's case.