You wake up to find icicles on your nose. You grumble, check the thermostat and check the breaker. Still nothing. Or on an early spring day, you move the thermostat to "cool," but the house stays "warm." You pick AAA Acme Fix-All from the yellow pages and are told the widget is broken and it will cost $900 to fix. Now what?

Your first mistake was not having already established a relationship with a reliable heating and air conditioning (HVAC) company. The best way to make sure that your system continues to run reliably and efficiently is to have preventive maintenance on the system at least once a year. Many HVAC installation and repair firms offer an annual contract that covers one or two preventive maintenance visits, plus priority if your system goes out on the first cold day and you're competing with half the county to schedule a service call.

How do you decide whether to repair or replace your system? If your system is more than ten years old and you face major repair costs, it's probably time to think about replacement. There is one consolation — upgrading to a new high-efficiency system may reduce your heating and cooling costs by 30 to 40 percent a year.

Signs that your system may be failing include frequent service calls; unusual noises; increased heating and cooling costs; your system's turning on and off frequently; and changes in the comfort level in your house. If your home has humidity problems or excessive dust, you may also have ducts that need sealing or replacing.

One of the most important factors in good performance of a heating and cooling system is that it be sized correctly. In air conditioning, in particular, bigger is not always better. In addition to the fact that larger systems cost more, if the system is too large for the house, the air conditioner or heat pump might not run frequently enough to keep the humidity at a comfortable level. For heat pumps and air conditioners, contractors should use the sizing manuals put out by the Air Conditioning Contractors of America (www.acca.org). The contractor should note the window area, the direction the house faces, and the insulation levels. This information is used to calculate the amount of cooling your house needs.

This is a major expense, so you'll probably want to compare costs from several contractors. To make a fair comparison, be sure the bids you are looking at are based on the same size and efficiency equipment and the same quality of workmanship. Also, ask about equipment and labor warranties.

If you have gas heat plus central air conditioning, you may want to consider replacing both with a new high-efficiency heat pump, which will save you money winter and summer. In summer, a heat pump takes heat from inside your house and sends it outside; in winter, it takes heat from the outside air and "pumps" it inside. There's enough heat in the outside air to heat your house even when the temperature is below freezing. By using the heat in the air, heat pumps create two to three times more heat energy than they use in electrical energy.

Whatever you choose, remember that you'll save money year after year with the small investment upfront for a more efficient system. Air flow — both supply and return — should be designed and measured. Ducts should be sealed for indoor air quality and energy efficiency. A Right Choice High Tech Audit will test the performance of your heating and cooling system.

Jackson EMC has financing for energy-related home improvements, including heat pumps. To find out more, call your local office.

How do you find a reliable contractor?

As with any major purchase, you should ask your friends and neighbors for referrals and check on companies' standings with the Better Business Bureau. Also, ask for references — and check them. A quality contractor will do more than just ask you the square footage of your home. Look for a company whose representative asks you about your experience with your heating and cooling system, including whether any rooms are particularly hot, cold or drafty. Look for dealers who have been in business several years. You want them to still be around if something goes wrong. Finally, get a written contract.