Location of Gas

• If you smell gas, you should be concerned about how far the smell is from the furnace. If the smell is near the furnace, it may not be a problem since gas furnaces sometimes emit an odor after starting up after a long time of disuse. It is also common for furnaces to emit an occasional odor. However, it's not normal to smell gas in other areas of your home; the presence of gas elsewhere suggests that you have a leak.
  
  

Frequency of Smell

• Smelling gas once in a while near your furnace is normal. Gas furnaces emit some gas every time you turn them on. Thus, you may occasionally notice an odor when you have been using your furnace. However, if you smell gas on a regular basis, get your furnace checked for leaks. You shouldn't smell gas every day if your furnace is working properly.
  
  

Starting Up Furnace

• If you haven't run your furnace all summer, don't worry about the smell when you first start it up. Dust builds up on the components when you don't use the furnace for a while. As a result, the dust burns when you first turn on the furnace, emitting an unpleasant odor. Wipe any visible dust off your furnace with a rag before starting it and open doors and windows to let the odor out.
  
  

Warnings

• It can be difficult to tell the difference between a normal gas smell and a leaky furnace. If you're in doubt, call your gas company. You may have to insist that the technician check the furnace, as he may chalk the smell up to normal wear and tear on the valves even if there's a problem. In addition, don't run your furnace unless you have a carbon monoxide detector installed in your home. Carbon monoxide poisoning is deadly, and this gas doesn't have an odor at all.