NATE Gas & Oil Forced-Air and Hot-Water Heating Systems Practice Test 2025 - Free NATE Practice Questions and Study Guide

The primary function of a fan control in a gas furnace is to start and stop the blower. This component is essential for managing the distribution of heated air throughout the living space. When the furnace heats the air, the fan control ensures that the blower operates at the appropriate times to circulate the warm air effectively.

By controlling when the blower turns on and off, the fan control helps maintain comfort levels and efficiency in the heating system. If the blower runs continuously or at inappropriate times, it can either waste energy or fail to provide the desired warmth, making the fan control a critical element of the operation of a gas furnace.

The other functions mentioned, such as regulating gas flow, controlling temperature settings, or measuring humidity levels, are typically managed by different components within the heating system, emphasizing the specific and crucial role of the fan control in the overall operation of a gas furnace.