A boiler typically lasts between 15 to 25 years, depending on the quality of the unit, usage, and how well it is maintained. Regular maintenance and annual inspections can help extend the lifespan of a boiler by identifying potential issues early and ensuring efficient operation. Factors like water quality, frequency of use, and the type of fuel used can also impact its longevity. To maximize the lifespan of your boiler, scheduling routine professional service is highly recommended.