A gas furnace is a heating system that uses natural gas or propane to warm your home. It works by igniting gas in a burner, which heats air that is then circulated through ducts. This type of furnace is popular because it can heat a space quickly and efficiently, making it a reliable choice for cold weather. Gas furnaces are often equipped with a thermostat, allowing you to set your desired temperature easily. Regular maintenance, like changing filters and checking for leaks, is important to ensure safety and efficiency. With proper care, a gas furnace can provide warmth for many years.