The main purpose of your furnace filter is to ensure that none of the additional materials your fans pull back into the unit - such as hair and dust - actually damage the furnace or its parts. In the process, it also improves air quality in your home. Some annual inspections will include changing and cleaning this part of the unit. That said, you can also clean or change your furnace filteryourself. Costs for new filters range based on brand, but tend to be around $30.
If you happen to live in a hot and humid area of the country, drainage problems can occur with your unit since moisture can trap itself inside the system. Routine maintenance can cut down on drainage issues by cleaning out any mold or algae from blocking the drain. If you notice moldy smells whenever you turn the thermostat down, check on your system.
Furnace breakdowns, no cooling when outside temperatures are soaring – heating and cooling repairs often catch us unexpectedly, making HVAC repair costs quite a surprise. Many homeowners worry when calling the HVAC repair contractor because of unexpected costs – your heating and cooling contractor won’t be able to give you a price for the repairs needed until he or she inspects the system to find the source of the problem.
High-efficiency condensing furnaces (90% AFUE and above) are a bit more complex than conventional furnaces. The main differences between a conventional and condensing furnace are the heat exchanger technology used to extract heat from the combustion process and the method used to exhaust the combustion gases. In these ways, the furnaces are very different. The condensing furnace does not have a significantly more efficient combustion process than does a conventional furnace; both use gas burners with electronic ignition. The difference lies in that the condensing furnace has a more efficient heat extraction process after combustion.
Start with your utility company; they can help a great deal. Comparing previous bills isn't always a good measure, as the weather is never exactly the same month to month. Instead, if you take your energy bill and divide it by the square footage of livable space in your home, don't count areas like unfinished garages or basements -- you can calculate how much you are spending to heat or cool each square foot of your home. Your energy provider can tell you what the average cost per square foot is in your region for that same period of time so you can compare apples to apples.
The contactor (relay) and start/run capacitor(s) (see illustration below) fail most often and are inexpensive. So it’s a safe bet to buy and install those parts right away, especially if your air conditioning service unit is older than five years. The condenser fan motor can also fail, but it runs about $150 — hold off buying that unless you’re sure that’s the culprit.
In addition to the information below, see these two articles for the general care and maintenance of your air conditioner: Preparing Your Air Conditioner for Summer and How to Replace Furnace & AC Filters. Most noteworthy, you should replace the filters at least twice a year, before the heating and cooling seasons. For information on furnace problems, please see Furnace Not Working.