The answer to 'what is boiler' is a central heating system that uses hot water or steam to heat a home or building. Boilers work by burning fuel, such as natural gas, oil, or propane, to heat water that is then circulated through a system of pipes and radiators or baseboards throughout the building. This hot water or steam provides the heat that warms the air and surfaces in the home.
Boilers are a common and efficient heating system, especially in colder climates. They are typically found in older homes and buildings, but are still installed in new construction as well. Boilers require regular maintenance and inspection to ensure they are operating safely and efficiently.