Which condition can cause a boiler to run inefficiently?

A boiler can run inefficiently due to the presence of air in the system. When air enters the boiler or the piping, it can disrupt the normal flow of water and steam. This presence of air can create pockets that impede water circulation, leading to uneven heating and potentially causing hotspots or areas of inefficiency within the system. Consequently, it may require the boiler to work harder to maintain the desired temperature, increasing energy consumption and reducing overall efficiency.

In terms of context, while other conditions like too much fuel, high pressure settings, or excess water levels can lead to operational issues, they typically affect the efficiency of the system in ways other than the circulating fluid dynamics, such as combustion efficiency or safety concerns. However, air in the system directly hampers the efficient transfer of heat, which is critical for the proper operation of a boiler.