Do I Have a Boiler or a Furnace?

“Do I have a boiler or a furnace?” It’s a good question because many people use the terms boiler and furnace interchangeably. While both units have things in common, they also have profound differences. In this article, we'll explore the differences between boilers and furnaces and teach you how to spot the difference.

Boilers

Boilers generate warm air by heating water and then circulating it throughout your home via baseboard heaters or radiators. While most residential boilers typically operate by burning heating oil or gas, electric boilers exist as well. Electric boilers use heating elements to heat water, while gas-powered boilers use gas jets for the same purpose.

Furnaces

A furnace uses heating oil, gas or an electrically powered forced-air system to generate warm air. This system heats the air through a device known as a heat exchanger. Once the heat exchanger produces heated air, it circulates throughout the home via ducts fed by blower fans. In electric powered furnaces, heating elements are present that create warm air.

Which do you have?

It’s quite simple to determine whether you have a boiler or a furnace. Head down to the basement and do a quick assessment:

• A boiler will connect to pipes or tubing, which are either copper or iron. Be mindful that sometimes, these items may be covered with insulation. Residential boilers also tend to be small box-like structures three to four feet in height.
• A furnace connects to ductwork, which most of the time stretches up to the ceiling. Ductwork is typically sheet metal, but sometimes it is constructed out of reflective fiberboard. Many times, this ductwork will be wrapped in reflective insulation.