The answer to 'when to replace boiler' is that you should typically replace your boiler every 15-20 years, or sooner if it is not functioning properly. Boilers are durable and can last a long time with proper maintenance, but they do have a finite lifespan. As a boiler ages, it becomes less efficient and more prone to breakdowns, which can lead to increased energy costs and potential safety issues.
It's important to have your boiler serviced annually by a qualified HVAC technician to ensure it is running safely and efficiently. They can identify any potential issues and recommend whether a replacement is necessary. Signs that your boiler may need to be replaced include frequent breakdowns, increased energy bills, and difficulty maintaining a consistent temperature in your home.