Top 6 Considerations When Buying a New Furnace

Learn the top things to consider when you’re in the market for a new furnace.

January 28, 2025

If your furnace went out during the latest cold snap, you need to do some quick research. Or if you read our blog on warning signs you need to replace your furnace, you may have a little more time.

In either case, we’ve pulled together some information to help you make an informed decision before buying a new furnace. Let’s start with the types of furnaces.

Different types of furnaces

There are four main types of furnaces. Each heats your home using a different fuel source. They include:

Electric furnaces They run on electricity and can be expensive to operate. While electric, they may get that electricity from a coal-burning power plant.
Propane furnaces These furnaces burn propane gas to heat your home. They are more common in rural or remote areas not served by a natural gas line.
Oil furnaces An oil furnace burns home heating oil. This fuel can be expensive. Oil furnaces are less common.
Gas furnaces Natural gas furnaces are the standard furnaces in the United States. They burn natural gas and are generally cheaper to operate than other furnace types.

According to the U.S. Energy Information Administration (EIA), around 60% of U.S. households use natural gas for heating, while only around 4% rely on heating oil, primarily concentrated in the Northeast region. This article will focus on what to consider when buying a gas furnace because that is our area of expertise.

What questions should I ask when buying a new furnace?

We won’t tell you exactly what to ask, because we’re not sure what matters most to you in a new furnace. We will give you some general topics to ask about, or research before you schedule estimates from local HVAC companies.

#1: Heating Stages

Furnaces can be single-stage, two-stage, or have variable-speed motors.

A single-stage furnace is either on or off. When the thermostat signals the need for heat, it comes on at 100% and when it reaches the set temperature it shuts down. It provides a bit more heat than is required and will overshoot the thermostat temperature causing larger temperature swings. This is more expensive to operate than a two-stage furnace.

A two-stage furnace has two heating stages. It can operate at 65% or 100% capacity, depending on your heating needs. A two-stage unit is more efficient than a single-stage unit and can provide more even heating.

The final type is a modulating furnace with a variable-speed blower motor. It can run at lower speeds, providing more precise heat circulation throughout your home. Coupled with a modulating gas valve that operates between 40% and 100% depending on your heating needs, this is the most efficient type of furnace.

#2: Energy Efficiency

Federal Efficiency Regulations have changed over the years and Furnaces have become more efficient. Today’s high-efficiency furnaces do a much better job of heating your home using less fuel.

Each gas furnace has an AFUE or annual fuel utilization efficiency rating, which is expressed as a percentage. AFUE measures how much fuel is used to directly heat your home and how much exhausts out of your home as flue gas.

High-efficiency condensing furnaces must have an AFUE of 90% or higher and are well-suited for northern climes. The higher the AFUE rating, the more efficient a furnace is, and the higher the price tag. However, the colder your weather, the more a high-efficiency furnace will run, and the sooner you will see energy savings and a reduction in operating costs.

A furnace with an AFUE of 80% might be suitable for a more moderate climate where you don’t need the furnace as much.

ENERGY STAR®-qualified furnaces have stricter criteria including reduced conditioned air leakage. You may want to purchase an ENERGY STAR® furnace if you want to be eligible for the energy tax credit.

#3: Sizing

What size furnace do I need? That’s a good question, and the answer will vary for every homeowner. You want the furnace to have enough heating output in British Thermal Units (BTUs) to keep your home comfortable on even the coldest of days.

Work with an HVAC professional to determine how many BTUs you need. They’ll perform a heat load calculation to help determine the right size furnace for your home. Square footage, insulation, ductwork, your climate, and many other factors should be taken into account.

A contractor should not just automatically recommend the same size furnace you currently have. Changes to your home over the years may affect your heating needs.

#4: Brand

Even if you’re loyal to a brand, it’s OK to look beyond that brand. Furnace technology has changed over the years and certain materials can last longer. Research the best furnace brands and dig deep into the product specifications for individual units.

Our furnace brochure can help you learn about what we have to offer and compare one furnace to another.

#5: Cost

A high-efficiency gas furnace from a premium brand such as American Standard will cost more upfront than a bargain or mid-tier brand. But our SEET-tested furnaces are built to last – with proper maintenance and usage, they can last 20 years or more.

Our heat exchangers come with a limited registered warranty of 20 years to back that up. To be eligible for the limited registered warranty, you or your dealer must register the product within 60 days of installation.

While new furnace cost is certainly a factor in your overall decision, we would argue that it shouldn’t be the deciding factor. Investing in quality now can save you money on long-term repair and utility bills.

Several factors will help determine your overall furnace replacement cost, including:

Your climate
Your heating needs
Your Fuel Type (Electric, Natural Gas, Propane, Fuel Oil)
The size and layout of your home
The number of heating stages
The AFUE rating
The brand
If you’re opting for a hybrid heat system
Labor costs where you live
And more

The best way to get accurate pricing for new furnace installation is to get quotes from HVAC contractors near you, which we’ll address in #7.

#6: Long-term savings

While a more efficient furnace may cost more upfront than a less efficient model, investing in quality now will reap financial benefits for years to come. There is a long-term financial impact of going with an 80% AFUE furnace versus a 97% AFUE furnace… i.e. if you have 4 months of a heating bill that is $250 each month, you’re essentially “throwing away” $200/year versus $30/year with a 97% furnace, and over the life of the furnace, that can add up quickly.

In addition to saving money, with a highly efficient condensing furnace, you’re also doing your part to decrease carbon emissions and save the planet.

#7: The HVAC contractor

Choosing the right HVAC company can be the difference between a properly sized and installed furnace and a furnace that gives you nothing but trouble. Do your homework to find the best HVAC service near you.

Work with the furnace experts

American Standard furnaces are designed to deliver premium indoor comfort with precise control and come in a range of options to fit each unique application. If you’re planning to purchase a new furnace, work with your American Standard dealer to find the home heating solution that’s right for you.

You might even consider opting for a hybrid heating system with a heat pump and gas furnace if you’re looking for a more sustainable heating and cooling system.

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Anne Fonda, Content Writer

A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.

She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism.

When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.

Expert review by Kimberly Sexton, Senior Systems Engineer