On average, boilers can last anywhere from 10 to 20 years. The lifespan of a boiler depends on several factors, such as the type of boiler, the quality of the installation, and the maintenance schedule. Boilers that are well-maintained and serviced regularly can last up to 20 years, while those that are not maintained properly may only last 10 years. Additionally, boilers that are exposed to extreme temperatures or are used frequently may need to be replaced sooner than those that are not.