The biggest and most obvious sign your furnace is going bad is that you’re paying for more frequent (and more expensive) furnace repairs. On average, you can expect a furnace to last 15- 20 years. It can last longer if well-maintained and fail earlier if poorly maintained. The quality of the unit will also affect how long a furnace lasts. If you smell something like burning plastic or a strong and unpleasant smell like formaldehyde, your furnace has serious issues. Turn off the power and call for immediate furnace repair. If you smell rotten eggs, that is the smell the gas company adds to natural gas to warn you of a gas leak. Leave your house immediately with your children and pets and call the gas company. Once the leak is found and the gas turned off, contact your HVAC company for a consultation. As an oil furnace or gas furnace ages, it becomes less and less efficient. That can mean increased heating costs even if you don’t need repairs. Another sign of a failing furnace is a decreased ability to keep your house warm. If your furnace is not kicking in when the temperature drops or the furnace is not blowing warm air, your comfort level will decrease.

furnace and ac replacement cost?

The biggest and most obvious sign your furnace is going bad is that you’re paying for more frequent (and more expensive) furnace repairs. On average, you can expect a furnace to last 15- 20 years. It can last longer if well-maintained and fail earlier if poorly maintained. The quality of the unit will also affect how long a furnace lasts. If you smell something like burning plastic or a strong and unpleasant smell like formaldehyde, your furnace has serious issues. Turn off the power and call for immediate furnace repair. If you smell rotten eggs, that is the smell the gas company adds to natural gas to warn you of a gas leak. Leave your house immediately with your children and pets and call the gas company. Once the leak is found and the gas turned off, contact your HVAC company for a consultation. As an oil furnace or gas furnace ages, it becomes less and less efficient. That can mean increased heating costs even if you don’t need repairs. Another sign of a failing furnace is a decreased ability to keep your house warm. If your furnace is not kicking in when the temperature drops or the furnace is not blowing warm air, your comfort level will decrease.

Energy Savings6min read

Furnace Replacement: A Buying Guide

Discover what you need to consider when it comes to furnace replacement in our handy buying guide.

Published:
January 23, 2025

By Anne Fonda

So, your old furnace finally gave up during the latest Dallas, TX cold snap or East Coast arctic blast. Or maybe the latest furnace repair costs made your jaw drop and made buying a new furnace a more cost-effective move than paying for more repairs. Or maybe you read our blog on warning signs that it’s time for furnace replacement and you came here next.

The bottom line is you’re in the market for a new furnace for your home, and as with any big purchase, you’re doing your homework. Smart move.

We’ll focus on gas furnaces rather than electric furnaces or other types of furnaces since natural gas furnaces are more economical and more widely used – and gas furnaces are in our area of expertise. Here are the top 6 things to consider when it comes time to buy a new furnace.

Consideration #1: Efficiency

New furnaces are much more efficient than older furnaces. Annual fuel utilization efficiency (AFUE) ratings describe how well a furnace utilizes the fuel it burns to heat your home. An AFUE rating is listed as a percentage.

The percentage describes how much of the fuel goes directly to heating your home and how much is exhausted out of your home as flue gas. The higher the AFUE rating, the more efficient a furnace is, and the unit’s carbon emissions are reduced when compared to a less efficient furnace.

Today’s high-efficiency furnaces are condensing furnaces. They have AFUE ratings of 90 or higher and utilize two heat exchangers to more efficiently heat your home while reducing wasted fuel. More efficient furnaces cost more upfront but can save you money on operating costs for years to come – 15 years or more, on average.

Trane furnaces typically last 20+ years and our heat exchangers have a 20-year registered limited warranty, while other parts have a 10-year registered limited warranty.

Modulating burners and variable-speed blowers make an efficient furnace even better, offering precise temperature control and peak efficiency.

Pro tip: Choose the most energy-efficient furnace you can afford for long-term savings.

Consideration #2: Proper sizing

A new furnace or HVAC system is only as good as the design and installation. An improperly sized system or improperly installed system won’t give you the temperature control and comfort you deserve. That’s why it’s important to work with an HVAC company with years of experience in HVAC system sizing.

Proper sizing and system configuration take much more into account than square footage. An improperly sized system will waste energy, which is the last thing you want to do. You want to make sure your furnace has enough BTUs to comfortably heat your home, whether you’re in Houston or Chicago.

Consideration #3: Upgrading your AC or heat pump at the same time

Our HVAC experts say it may be OK to replace only the furnace if your air conditioner or heat pump is relatively new and compatible with the furnace you decide on. But if your cooling unit is as old or older than your furnace, you will want to plan on replacing the entire HVAC system at one time.

Installation will be more cost-effective that way, and the system components will work well together for maximum efficiency. Learn more about full system replacement in our HVAC replacement guide.

Consideration #4: Furnace replacement cost

Your gas furnace replacement cost will depend on several factors. The same goes for AC/furnace replacement costs. Some of these factors include:

Your climate and heating and cooling needs
The size and layout of your home
Your home’s insulation
Complexity of the installation
Whether you need new ductwork
If you’re replacing an oil furnace or a natural gas furnace or doing a conversion from oil to gas
The brand you choose – lower-priced brands may not last as long as premium brands
The efficiency of the units (SEER2, AFUE)
Single-stage, two-stage, or variable-speed system
Additional features such as a zoned system, humidifier, etc.
Available tax credits or rebates

View our Pricing Guide for some national average price ranges for various units. The best way to find out the cost of furnace replacement or furnace and AC replacement is to contact HVAC professionals in your area directly.

Consideration #5: Product reviews

Read product reviews for the HVAC products you’re considering. If you’re in the market for a Trane furnace, you can find the reviews at the bottom of each product page. You can also Google a model number or model name and read those reviews. What do people like about a certain product? What do they dislike, if anything?

Reading these reviews can help you ask some important questions when you get estimates.

Consideration #6: Hiring the right HVAC contractor

Working with the right HVAC company will go a long way towards you being satisfied with your new furnace or HVAC system. You want an HVAC contractor who listens to you, answers your questions thoughtfully, and helps you make an informed choice.

But you also want more. You want someone you can trust to do the job right, including sizing the system and installing it, without cutting corners or “eyeballing” it. If you are a new homeowner or new to the area and don’t know who to call, read our blog on choosing the right HVAC contractor for some tips on finding an HVAC company you can rely on.

Get a free furnace replacement estimate

Find one or more Trane dealers near you to set up an in-home consultation. Ask as many questions as you can to make sure you know what goes into replacement furnace cost or air conditioner and furnace replacement cost.

While cost shouldn’t be the sole factor you consider, we realize it is a concern for homeowners. Be sure to ask about any rebates or tax credits that can make a new furnace or HVAC system affordable. Ask about financing as well.

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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