NATE Gas Heating Test 2025 – 400 Free Practice Questions to Pass the Exam

The purpose of a gas valve in a furnace is to regulate the gas supply to the burners. This component is crucial because it ensures that the right amount of gas flows to the burners for combustion. Proper gas regulation directly influences the efficiency and safety of the heating process. If too much gas is allowed to flow, it could lead to unsafe conditions, including the risk of fire or explosion, while insufficient gas supply can prevent the furnace from operating effectively, resulting in inadequate heating.

In contrast, the other options address different aspects of furnace operation. While controlling airflow, maintaining proper venting, and igniting gas are important functions within a heating system, they do not pertain directly to the primary function of the gas valve. The gas valve specifically focuses on managing the supply of gas, making option C the most accurate choice regarding the role of the gas valve in a furnace.