What is the life expectancy of older conventional efficiency, cast iron boilers?

The life expectancy of older conventional efficiency cast iron boilers is typically between 35 to 50 years. This considerable lifespan is due to their robust construction and durable materials, such as cast iron, which can withstand high heat and pressure. This longevity is often attributed to the slow cooling rate of cast iron, which reduces the stress placed on the boiler during operation. Therefore, it is not unusual for well-maintained cast iron boilers to function effectively and efficiently for several decades, making this lifespan estimation an accurate reflection of their reliability and durability in heating systems.

In contrast, shorter lifespan estimates, such as 5 to 10 years or 10 to 15 years, would be more applicable to less robust systems or modern boilers that may not be constructed with the same durability in mind. The 15 to 25-year range, while a step closer to reality, still underestimates the potential of good-quality cast iron boilers, especially if they are regularly maintained.