What does a two-stage gas valve provide in a furnace?

A two-stage gas valve is designed to provide two levels of heating output, allowing a furnace to operate at different capacities depending on the heating needs of the space. This feature is beneficial because it enables more precise temperature control and can lead to increased energy efficiency. When the demand for heat is low, the furnace can operate in the lower stage, which uses less gas and produces less heat; when the demand is higher, it switches to the high stage to meet the increased heating requirements.

This capability helps to maintain a more consistent and comfortable indoor temperature while also reducing energy consumption during milder weather when full capacity is not needed. As a result, a two-stage gas valve plays a critical role in optimizing heating performance and operational efficiency in gas furnaces.