In a heating system, what happens if a crossover bridge is installed between the supply and return mains?

Installing a crossover bridge between the supply and return mains in a heating system allows water to flow from the supply to the return. This occurs because the supply side typically has higher pressure due to the pump forcing heated water into the system. When a bridge is introduced, the greater pressure on the supply side causes the heated water to flow into the return side.

Additionally, the flow direction is significant for proper heat distribution within the system—ensuring that the return lines receive the heated water efficiently for further heating cycles. This design allows for better heat transfer, avoids stagnation, and keeps the system balanced by ensuring heated water re-enters the boiler or heat source effectively.

While other options might suggest various conceptual scenarios, they do not accurately reflect the dynamics of fluid movement and pressure differences present in the heating system setup when a crossover bridge is installed. Understanding these principles is critical for maintaining efficiency and functionality in heating systems.