What does the thermostat control in a noncondensing gas furnace?

The thermostat in a noncondensing gas furnace primarily controls temperature settings by regulating the heating system to maintain the desired indoor temperature. When the room temperature drops below the set point on the thermostat, it sends a signal to the furnace to initiate the heating cycle. This process involves activating the ignition system, which lights the burner to generate heat, and ensuring that the heat produced is distributed effectively throughout the space.

Understanding the thermostat's function in regulating temperature is crucial, as it directly impacts the overall efficiency and comfort of the heating system. It allows homeowners to customize their heating to match their preferences and adjust for changes in weather or occupancy, ultimately leading to efficient energy use.

While the other options relate to components of the gas furnace system, they do not directly describe the primary role of the thermostat. For instance, the fuel supply is managed separately by the gas valve, and the draft fan operates based on the system's need for venting and combustion air, which are influenced by but not controlled directly by the thermostat.