do not often use natural gas forced hot air systems. This is due to the financial impracticality of running natural gas lines many miles past areas of relatively sparse habitation. Usually these rural and remote buildings use oil heat or propane, which is delivered by a truck and stored in a tank on the property. References Information on forced air pilot lights and maintenance from GasFurnaceGuide.com External links From howstuffworks.com Info about Forced-Air Furnace Heating Systems from hometips.com Residential heating appliances