How does a gas valve operate in a gas heating system?

In a gas heating system, the gas valve plays a critical role by regulating the flow of gas to the burner, ensuring that the right amount of gas is delivered for combustion. This regulation is essential for the efficient and safe operation of the heating system. When there is a demand for heat, the thermostat signals the gas valve to open, allowing gas to flow to the burner. Conversely, when the demand for heat decreases, the valve closes to stop the flow of gas. This operation not only optimizes performance but also enhances safety by preventing gas leakage when it is not needed.

The other options are related to different functions or components within a heating system. For instance, while the gas valve plays a role in safety and efficiency, it does not directly measure the outside temperature, control combustion gas temperatures, or measure the pressure in the gas supply line. Those functions are managed by other system components designed specifically for those purposes.