Boiler vs. Furnace: What’s the Difference?

Service Today

 Sometimes, boilers and furnaces are referred to interchangeably. However, they are substantially different from one another in how they generate heat. The simplest way to describe it is: 

A furnace heats air while a boiler heats water.

Boiler vs. Furnace

Here is a closer boiler vs. furnace comparison to help you better understand the differences.

How a Boiler Works

A boiler, or hydronic heating system, provides heating in your home by:

  • Heating water using natural gas, oil, or electricity. Some even use wood pellets.
  • Pumping hot water via cast iron radiators, baseboard radiators, or radiant flooring systems.

Radiant heating does not require a blower to deliver warm air. Heat radiates upward, which can provide a sufficient level of comfort throughout your home.

Boilers are also advantageous because they:

  • Are less noisy
  • Are energy efficient
  • Require no ductwork
  • Can reuse heated water
  • Are less likely to leak (but leaks can cause extensive damage)

How a Furnace Works

A furnace provides heating for your home by:

  • Heating air that passes through a chamber, using natural gas, propane, or electricity to generate heat.
  • Pushing heated air through ductwork using a motorized blower system.

Furnaces have a few advantages of their own, including:

  • Lower cost of installation
  • Reduce installation time
  • Less likely to freeze in winter, or during a power outage

However, a furnace can contribute to a drafty environment, allergies, and the spread of dust and dander, especially due to potential ductwork issues.


In the boiler vs. furnace discussion, maintenance is another area where each differs:

  • Boilers require little or no maintenance. A professional tune-up once a year is enough. 
  • Furnaces not only require annual inspections. The air filter must be changed monthly or quarterly for the unit to run properly.


The longer your heating appliance lasts, the more you will get out of your investment. A boiler can last as long as 30 years and requires fewer repairs in general. However, a furnace might last 15 to 20 years if it is properly maintained.

When to Choose Between a Boiler vs. Furnace

Both options work alongside air conditioning systems to provide cooling. However, this might require additional ductwork or alternative ductless systems to be installed. While boilers are generally more costly to install, they can use less fuel, which may reduce operating costs. 

But what’s best for your home depends on your needs and preferences. There are many factors to consider when weighing one over the other. Energy efficiency is one, but can be improved further by installing solar panels, which can reduce monthly energy bills and help the environment.

However, there are both high-efficiency boilers and furnaces on the market today. Many have annual fuel utilization efficiency (AFUE) ratings from 90% up to 98.5%.

Contact Service Today!

Our experienced team specializes in boiler and furnace repair, installation, and maintenance. When you need a tune-up, Service Today! technicians can improve efficiency and address any minor issues to maximize reliability and safety. We can even help you decide between a boiler vs. furnace if it’s time for a replacement. To request heating service in your area, contact us today or call (888) 395-0085.