The answer to 'how long will boiler last' is that a well-maintained boiler can typically last 15-30 years, depending on the type of boiler and how it is used. Properly servicing the boiler and addressing any issues promptly can help extend its lifespan. Factors like the quality of the installation, the water treatment, and the frequency of use can all impact how long a boiler will last.
Older boilers, especially those over 20 years old, may start to become less efficient and require more frequent repairs. As boilers age, it's important to monitor their performance and consider replacing the unit if it becomes too costly to maintain or is no longer meeting your heating needs.