A gas furnace is a smart choice for your home heating needs. When you are shopping for a new Trane furnace, it may be helpful to learn more about how a gas furnace works to heat your home. This type of heater relies on the process of heat combustion to create heated air. When natural gas is ignited in the furnace combustion chamber, it naturally heats air that is located inside the furnace. After the air has been heated through combustion, it is sent to your interior spaces through a series of air ducts. In order to know when to heat your home, a gas furnace relies on a thermostat sensor. When the sensor on the thermostat detects that the temperature of a room has dropped below a certain level, the gas furnace will automatically switch on. A company offering furnaces in Portland will be able to answer all of your questions about furnace repair and operation.