Fixing Forced-air Furnace and Heating Problems
Most heating systems operate reliably for a long time if they are well-maintained. Before you call a furnace technician for a repair or roll up your sleeves to do the work yourself, call your utility or check their Web site–in many areas, the utility company will send a technician to your home to check minor furnace problems for free.
If you smell gas in your home or near your furnace, particularly if the odor is strong, immediately evacuate the house, leave the door open, and call your gas utility or the fire department from your neighbor’s house or a cell phone. (Don’t use the phone in the house or turn light switches off or on.)
Sometimes a furnace may not seem to be generating any heat. In this situation, check the master switch and circuit breaker or fuse. The electrical system may have overloaded. If you don’t find a tripped circuit breaker or blown fuse, your thermostat may be faulty.
Other problems you may encounter with your forced-air furnace are insufficient heat, a blower that doesn’t work, a noisy blower, too much heat, or a room temperature that does not match your thermostat setting.
Caring for Your Furnace
Clean or replace a disposable furnace filter periodically during the winter–check the filter monthly. Brush and vacuum the heat exchanger surfaces every year, if recommended by your owner’s manual. Before the heating season, clean the blower blades and seal any air leaks in ducts with several wraps of duct tape.
Source:http://www.hometips.com/content/forcedair_tp.html