What’s the Difference Between a Furnace and a Boiler: Step-by-Step Comparison

Whats the Difference Between a Furnace and a Boiler Step by Step Comparison

Table of Contents

When it comes to heating systems, the terms “furnace” and “boiler” are often used interchangeably, leading to confusion about their distinctions. Understanding the differences between these two heating systems is crucial for homeowners, renters, and anyone seeking to make informed decisions about their heating needs.

From how they generate heat to the fuel sources they utilize, furnaces and boilers have unique characteristics that set them apart. In this article, we will discover the major difference between boilers and furnaces, their working principles, main fuel sources, pros and cons, and unit prices.

Working Principle of a Boiler

The working principle of a boiler is similar to boiling water for tea. The unit heats water using a fuel source, mainly natural gas or oil. The heated water is then circulated and used as hot water in pipelines or steam. It is distributed through different pipelines to provide warmth or power to different areas or processes. The boiler’s controls help to maintain the desired temperature and pressure while the exhaust system removes waste gases. We will discover the difference between a boiler and furnace further in the following paragraph.

Working Principle of a Furnace

In simple terms, a furnace uses fuel to create heat. The most popular energy sources are natural gas, electricity, propane, or solar energy. All of them are used to warm up the air in a building, which is further distributed through vents around the house. The heating process is controlled by a thermostat, which turns the furnace on and off to maintain the desired temperature.

Statistics Canada says that Canadians mostly choose furnaces in the boiler vs furnace battle. In 2021, 51% of households owned a forced air furnace, while only 8% had boilers with hot steam or water radiators.

Cost of Boiler vs Furnace

The most interesting topic for all buyers is the prices of a boiler and furnace. A new boiler unit will cost around $1,200 – $5,000+ without installation. With professional services from a licensed team, you will pay on average $3,500 to $10,000+ for a combi boiler and $5,000 – $10,000+ for a conventional boiler.

The average furnace cost starts at $4,000 with installation included. It is important to mention that prices may be lower or higher, depending on several factors, including the following:

  • Size of your home. Add at least 20 BTUs to each square foot of your apartment.
  • Level of efficiency. It is measured in Annual Fuel Utilization Efficiency (AFUE). The higher these numbers are, the less fuel your unit uses to heat the apartment.
  • Fuel type. The most expensive boilers run on natural gas, oil, or wood, while the most costly furnaces use natural gas or propane. Their prices start from $4,000, including installation.

If you want to receive precise calculations for your case, schedule a free in-home assessment from the HVAC Service Solutions via the link below:


Furnace vs Boiler Efficiency

Furnace vs boiler efficiency is one of the major features to consider before buying. Mid-efficient units cover the range of 80%-88% AFUE, while high-efficiency have from 90% to 98.5%.

The higher the rates are, the less energy your equipment will use to produce heat. If your unit has 80% of efficiency, it will convert 80% of fuel into heat. The 20% are lost. Let’s compare the system’s efficiency, depending on the fuel source.

Fuel Source
Boiler AFUE
Furnace AFUE
40% – 90%
40% – 90%
87% – 91%
85% – 96.7%
90% – 97%
91.2% – 99%
Natural Gas
90% – 97%
91.2% – 99%
99% – 100%
99% – 100%

The data is based on the US DOE Energy Star pages for boilers and furnaces.

Note that both boilers and furnaces should be maintained at least once a year. In that case, the AFUE rates will remain high, and the system will work efficiently during its lifespan.

If you want to get your units checked, order professional services from HVAC Service Solutions via the link below.


Boiler vs. Furnace Monthly Cost

The monthly cost of operating a furnace vs boiler can vary depending on several factors, including the energy source, system efficiency, insulation of the building, climate, and individual usage patterns.

Note that high-efficiency boilers and furnaces will have lower monthly operating costs due to their ability to extract more heat from the fuel. It’s recommended to consider the specific characteristics of your building and consult with local HVAC contractors to obtain more accurate cost estimates based on your location and energy prices.

You can schedule a visit from the HVAC Service Solutions expert in 60+ service areas. Follow the link to find the nearest place:


What's the Difference Between a Furnace and a Boiler

The main difference between a furnace and boiler is their working principle. A furnace heats the air directly and circulates it through ductwork, while a boiler heats water or produces steam, which is then distributed through pipes to radiators or other heat emitters. Some of the other differences are added to the table below.

System Lifespan
20 – 30 years
15 – 25 years
Fuel Source
Natural gas, oil, propane, biomass (such as wood pellets), electricity
Natural gas, oil, propane, electricity
Radiant, requires a separate cooling system
Forced, combined with a central system
$3,500 – $10,000+
$3,000 – $6,500+

Pros and Cons of Furnace

Furnace Pros
Furnace Cons
Low prices
Low efficiency
Reduced leak or freezing hazard
High noise levels
Easy installation
Reduced heat consistency
Connected to the central system
Low indoor air quality

Pros and Cons of Boiler

Boiler Pros
Boiler Cons
High energy efficiency
Complicated installation
Consistent heat
Leaking or freezing hazard
Low noise levels
Delayed heating response
Less maintenance
Big space requirements
High indoor air quality
High installation costs

If you want to learn which is better: a boiler or a furnace for your house, contact our HVAC Service experts via the link below. They will consider all technical characteristics and your personal preferences to find the perfect solution.



If you are still contemplating which is best for your house, a boiler or furnace, we are here to help. The HVAC Service Solutions works in 60+ service areas around Canada to provide the desired services on the same day.

Follow the link to hire a certified HVAC contractor at any time of the day: