What is the required gas pressure at the manifold and burners for a natural gas furnace?

The required gas pressure at the manifold and burners for a natural gas furnace is typically set at 3.5 inches of water column (WC). This pressure is essential for the proper operation of the furnace, ensuring that the burners receive a sufficient and consistent supply of gas for efficient combustion. At this pressure, the gas can mix adequately with air, providing optimal combustion efficiency and minimizing the risk of incomplete combustion, which could lead to safety hazards like carbon monoxide production.

Setting the pressure correctly helps in achieving not only efficiency in heating but also in maintaining safe operating parameters for the furnace. Deviations from this standard pressure could lead to issues, such as poor heating performance, increased fuel costs, or even dangerous conditions if the gas does not burn correctly. Thus, ensuring the pressure is set at the manufacturer's specifications, usually at 3.5" WC for natural gas appliances, is crucial for safe and efficient furnace operation.