What is the primary function of a gas furnace?

The primary function of a gas furnace is to provide space heating by using gas as its fuel. Gas furnaces operate by igniting natural gas or propane, which generates heat that is then distributed throughout the living spaces of a home. This heating process is essential during colder months, ensuring that indoor temperatures remain comfortable and safe for occupants.

In contrast to other options, using electricity as fuel is specific to electric furnaces, which function differently and may not serve all the needs of typical residential heating systems. Providing hot water is the role of water heaters or boilers, not gas furnaces, which are primarily focused on air heating for living areas. Cooling indoor air is the function of air conditioning systems, which work on an entirely different mechanism than gas furnaces, highlighting the distinct purposes of each type of system in residential settings.