The answer to 'how often to replace boiler' is that the average lifespan of a boiler is 15-30 years, depending on the type, quality, and how well it is maintained. Most boilers will need to be replaced every 15-20 years, though high-efficiency models may last up to 30 years with proper care.
Factors that affect a boiler's lifespan include the quality of the unit, how often it is serviced, and the water quality in your home. Regular maintenance, such as annual tune-ups and cleaning, can help extend the life of your boiler. However, even well-maintained boilers will eventually wear out and need to be replaced to ensure safe, efficient, and reliable home heating.