What happens when a boiler heat exchanger has cracked?

When a boiler heat exchanger has cracked, it leads to a breach in the system that can cause water to leak. This leak can occur intermittently, and the severity of the leak can vary depending on the location and size of the crack. Since the heat exchanger's primary function is to transfer heat, any damage compromises its integrity, often resulting in leaks during operation when pressure builds up inside the system.

This scenario is typically characterized by water escaping the system at various times, particularly under conditions where heating occurs and the pressure is elevated. As a result, the situation may not be constant; instead, it can manifest as sporadic leaking, validating the assertion in the chosen answer about the nature of the leak.

This phenomenon can be detrimental to the overall performance of the boiler and can lead to more significant issues if not addressed promptly, including potential equipment failure or additional damage to surrounding structures.