The Gas Furnace

A gas furnace is a large box-like applicance designed to heat a home. It works by first taking in the cold air in your house, then cleaning and filtering it with an air filter, then heating the air via a gas burner that uses a heat exchanger made of stainless steel, then distributing the heated air throughout your home through ductwork with a blower motor.

It is basically a continuous cycle of filtering and heating the cold air in your house. After the warmed air cools down again it travels through return air grills and ductwork and returns to the furnace. The cool air goes back into the furance intake and the process is repeated. It some scenrarios a humidifier is attached to the furnace or return air duct work.

Furances are available in varying efficiencies that are measured in AFUE (Annual Fuel Utilization Efficiency).

On occassion a gas furnace will stop working correctly and some form of maintenace must be performed to restore your unit to its original condition. On some older furnaces a common "heating service" is as simple as relighting a standing pilot, but most newer units need special trouble shooting because of their electronic ignitions.