In a natural circulation hot water heating system, what component collects excess water?

In a natural circulation hot water heating system, the expansion tank plays a crucial role in maintaining system pressure and collecting excess water. As the water in the heating system is heated, it expands; this increase in volume creates pressure that needs to be managed to prevent damage to the system. The expansion tank provides a space for this excess water to expand into, thereby absorbing the increased volume and preventing pressure build-up.

The expansion tank is designed to accommodate the fluctuations in water volume caused by temperature changes. This flexibility ensures the overall safety and efficiency of the heating system, as it helps maintain optimal operating conditions. Without an expansion tank, excess pressure can lead to leaks or even catastrophic failure in the piping system. Thus, the correct identification of the expansion tank as the component that collects excess water is vital for understanding how natural circulation hot water heating systems function.