What is one consequence of the presence of scaling in boilers?

The presence of scaling in boilers leads to potential overheating or failure due to a few key factors related to heat transfer and thermal efficiency. Scaling occurs when hard deposits, usually consisting of minerals, accumulate on the heat transfer surfaces of the boiler. This buildup acts as an insulating layer, reducing the efficiency of heat transfer from the combustion gases to the water.

When scaling takes place, the boiler requires more energy to achieve the desired temperatures since heat is not effectively transferred. This inefficiency can lead to overheating of the boiler components, as the surfaces reach higher temperatures to compensate for the poor heat transfer. Additionally, if the pressure and temperature exceed safe operational levels, it can jeopardize the structural integrity of the boiler, potentially leading to failure, such as ruptures or leaks.

In summary, scaling interrupts effective heat exchange, elevates temperatures excessively, and increases the risk of boiler malfunction, thereby making the option referencing potential overheating or failure the correct choice.