Which component is primarily responsible for directing the gases of combustion in a boiler system?

The component primarily responsible for directing the gases of combustion in a boiler system is the turnaround chamber. This chamber plays a critical role in the overall efficiency and safety of the boiler. Its main function is to collect and redirect the hot gases produced during combustion toward the heat exchanger, ensuring that the maximum amount of heat is transferred to the water or steam.

By properly directing the combustion gases, the turnaround chamber helps maintain optimal temperatures within the system and enhances the boiler's performance. It also helps in minimizing the formation of soot and other deposits that could hinder efficiency, thereby extending the life of the equipment.

In contrast, the other options serve different purposes in the boiler system. The heat exchanger is responsible for transferring heat from the combustion gases to the water but does not direct the flow of gases. The blowdown system is focused on maintaining water quality by removing impurities from the boiler. Lastly, the water tank stores water for the system but does not play a role in gas direction.