Boiler vs. furnace: what's the difference? | Thiele

Boiler vs. furnace: what’s the difference?

Boiler vs. furnace: what’s the difference?

Both boilers and furnaces can be used to heat homes. Thiele Heating and Air Conditioning has served central Indiana since 1883 installing equipment. As well as maintaining and repairing systems, our team understands the needs of Hoosier homeowners. Our top priority is providing reliable heating systems and comfort to your family. Part of our mission is providing insight into the different heating systems suitable to our region.

There are distinct differences between boilers and furnaces. For homeowners considering what system is best for your needs, exploring the benefits and disadvantages of each heating system helps make an informed choice.

Generating Heat

Both boilers and furnaces use natural gas, propane or electricity to generate heat. So the primary difference is heat from hot liquid or heat from forced air.

A boiler heats liquid in a central location and distributes the heat throughout your home. Pipes may be installed along flooring, walls and ceilings. If you imagine classic radiators and radiant flooring, then you form a picture of how heat moves from boilers into your home. Heat is transferred from liquid in the pipes to surfaces and the air within your home. Because surfaces like flooring conduct heat, boilers are very efficient methods for warming specific areas of your home.

A furnace heats air in a central location and circulates the heated air throughout your home. Ventilation systems move warm air into each room of your house and remove cold air through return vents. Modern furnaces are very efficient but generally heated air is dry.

Indoor Air Quality

Generally, a boiler system offers better indoor air quality than a gas furnace alone. Radiant heating and radiant flooring systems transfer heat through surfaces. Furnaces transfer heat directly into the air. This difference means furnaces are associated with common winter ailments. For homeowners who experience static electricity, irritated sinuses, itchy skin, dry coughs and general discomfort during winter, dry air is often the underlying cause. Many furnaces benefit from whole house humidifiers to increase indoor air quality.

As well as dry air, carbon monoxide, dust and airborne debris may also increase when air circulates through the furnace and ductwork. Cleaning ducts, maintaining furnaces and modifying furnaces can improve these issues. Contemporary furnaces and HVAC systems benefit from whole house humidifiers, air cleaners and air purifier modifications. All of these options improve indoor air quality. Carbon dioxide emissions and even carbon monoxide poisoning may occur when heating systems are not well maintained or malfunction. Our team tests operations to make sure boilers and furnaces are providing the best indoor air quality possible.


Most often, the initial purchase price and installation costs means furnaces are far more popular than boilers. If a home is not equipped with a boiler system, retrofitting pipes can be an invasive process. In these cases there is a clear difference in cost between boilers and furnaces. Since furnaces use the same ductwork as air conditioning systems, installing a furnace is typically less expensive. When you consult a professional HVAC contractor the ideal options will be presented. There are factors such as longevity and maintenance costs to consider. Asking for insight from your contractor assures you choose the best system for your home.


High efficiency boilers may require less energy than many furnaces. Also boiler systems typically produce less noise pollution when operating within a home. Depending on the location and design of forced air systems, furnaces can be disruptive and produce noise when hot air is cycling throughout your home.

Heating costs are a major expense for homeowners. While the energy efficiency of boilers is impressive, annual fuel utilization efficiency of gas furnaces continues to improve. When professionally installed and maintained by Thiele, your high efficiency heating system provides comfort without dramatically higher energy costs.

Cleaning, maintaining and repairing boilers and furnaces requires professional skill, tools and training. Both systems require unique maintenance. When comparing boilers and furnaces annual maintenance is sufficient to provide long lasting performance.


Both boilers and modern furnaces are very durable. The equipment installed by Thiele is built to last. Whether you choose a furnace or boiler, Thiele carefully matches the right system for your home. The size of your home, the space available for new equipment and the unique needs of your household are always considered by our team. Most often, homeowners choose to replace a boiler or a furnace based on the existing design of your home. For homes equipped with a boiler system, the advantages of improved comfort and efficiency often negate the additional cost. For homeowners replacing a furnace, cost and prompt installation is usually the top priority.

How to Choose the Best Heating System for Your Home

Purchasing a new heating system is a significant expense. More notably, Indiana winters are frigid so heating systems must be durable and reliable to guard against the elements. While there is a wealth of information and advice on the best heating systems, every household and home is unique. There is no single solution for all homeowners so we recommend consulting with our professional HVAC professional. The team at Thiele Heating and Air Conditioning provides comprehensive consultation to our customers. All highly skilled and professional HVAC technicians take time to listen to the needs and goals of homeowners. Whether you need service for a broken system or you are beginning the search for the best system to install in your new home, Thiele understands every family is unique. We provide insight, clarify questions and install durable, long lasting solutions for our customers.