Furnace Installation & Replacement St. Louis

A dependable heater is a staple of any modern home in the winter. Once it reaches the end of its shelf life, however, your furnace will need to be replaced. This inevitable expense means you need a dependable furnace installer you can trust to put in a more up-to-date unit when the time comes, so why not rely on a company with proven success?

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For over 100 years, Design Aire has provided furnace repair, furnace maintenance, and reliable furnace installation and replacement throughout the St. Louis and St. Charles areas. Our team has been recognized for excellent service through various awards and accolades, including being awarded as the Midwest’s #1 Trane dealer for over a decade.

Signs That It’s Time For A New Furnace

Although your heater might still function well, it’s important to know the signs that it might be time to consider furnace replacement or heating maintenance before your heating system quits working altogether. Some signs that your furnace might be reaching the end of its functionality include:

  1. Furnace age – Is your furnace close to 15 years old? Most models last 15 to 20 years, but if yours is older than that, it’s important to consider replacing it sooner than later.
  2. Furnace blows cold air – Your heater should, naturally, blow warm air to heat up your room. If it’s not doing this basic function, that could be the sign that you need furnace maintenance, or furnace repair services, or might be better off just replacing it with a newer, more efficient model.
  3. Strange noises – A furnace should not be so noisy that you start worrying about it. If you’ve noticed odd sounds coming from it that weren’t occurring before, there could be loose components signaling it has reached the end of its usability.
  4. Heating bill has increased – If your electric bill during the colder months is higher, but your usage has stayed the same, there is probably a problem with your furnace and it’s time to talk to a technician.
  5. Burner light is yellow – The flame on a heater should normally burn blue, indicating optimal performance. However, if your burner light burns yellow instead, it is not reaching peak performance and needs a technician to take a look at what’s wrong.
  6. Blows dust – If your vents have dust blowing out, but your air filter has been recently replaced and there is no other reason for dust to blow out, your heater is likely working poorly and may fail altogether soon.
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Fast & Affordable Furnace Installation From The Professionals

When thinking about heater replacement, an old, inefficient heater is important for your family’s comfort and, oftentimes, their overall health as well when the winter months (and cold temperatures) set in.

A warm home is a happy home, and working with an experienced technician team like the one at Design Aire will help with new furnace installation in your home in no time.

We work with all makes and models and you can work with us to receive special deals on Trane products. We are the #1 Trane dealer in the Midwest and receive quantity discounts on equipment, meaning you get the best product Trane has to offer paired with our high-quality customer service.

When your heating system fails, you need a reliable heating service that can get a new furnace running as quickly as possible. We offer furnace replacement and furnace installations with more efficient models for reasonable rates. And, because we have been around for over 100 years, you know we will provide the service you expect with the values our founder, Frank Fischer, used as a foundation when he started Design Aire: “Do a good job at a fair price and treat people right.” We do business by those simple words every time we provide service for a customer, whether it’s basic maintenance for a heater or putting in a whole new HVAC system.

What to Consider When Replacing a Furnace

Furnace Size

When an electric furnace or gas furnace reaches the end of its life, you may think simply getting a replacement unit with the same heating capacity as your old one is the solution, but that isn’t necessarily the case. The “size” of your furnace system refers to how much heat is put out (how much heat it can produce in an hour). Installing the correct size furnace is essential to the efficiency, reliability, operation, sound levels, comfort, and ongoing costs of heating your home.

Instead of basing your furnace size on only your home’s square footage, have a qualified heating expert evaluate your home to help you choose the right size system. They will take into account things such as the construction of your home, its windows, how well it is insulated, and the age of the home in addition to square footage to determine the heating capacity you’ll need to keep your house warm and comfortable.

It is important that the furnace is not too large for the space it is heating when thinking of a heating replacement. An oversized furnace will cycle on and off more frequently and will blow out much more air than is needed. Also, a short cycling furnace can leave hot and cold spots in your home and will not provide the same level of comfort as a properly sized furnace. It will also require more maintenance and heating repair and ultimately fail much sooner than a properly sized furnace.

Furnace Efficiency

Understanding furnace efficiency ratings can help you choose a new unit that will allow you to recoup the cost of a new furnace thanks to reduced energy bills. Furnaces are available in 80%, 90% or 95% efficiency. The higher the efficiency, the lower the utility costs. Usually, older gas furnaces are 65% efficient, so no matter what, you will typically see a reduction in the gas bill after a new furnace installation. However, the higher the efficiency of the new furnace, the bigger the reduction. You can decide whether choosing a higher efficiency unit is worth the extra cost for the natural gas furnace upfront based on your heating needs.

Single-Stage vs Two-Stage Furnace

Flexibility is the main difference between one-stage and two-stage furnaces. A furnace with single-stage heating has a single power mode: on. This means it is either on and running at full power or off. A unit with two-stage heating can operate at two different power levels: high power and low power. This allows the furnace to run at a lower setting in milder weather and a higher setting in very cold weather to help your home reach your desired temperature.


  • Single-stage – The main advantage is cost. Because this furnace type’s design is relatively basic in comparison to a two-stage unit, it is the least expensive type to purchase when looking at furnace prices.
  • Two-stage – The ability to switch between two power modes makes these furnaces more energy-efficient than their single-stage counterparts. The low power mode allows the unit to conserve energy as well as reduce temperature fluctuations and uneven heating in your home.


  • Single-stage – It can be problematic when it comes to heating a large or multi-story home. Because the furnace will run at full power whenever it is on, the areas near the vents will warm up quickly. The rest of your home might still be warming up when your thermostat thinks that your whole house has reached your desired temperature and shuts the furnace off prematurely, resulting in warm and cold spots around your home.
  • Two-stage – The improved comfort and lower energy bills come with an initial drawback, as these can cost more than a single-stage unit.

To prevent cold spots, many homeowners will raise the desired temperature on their thermostat so that the furnace won’t shut off so early. While this does solve one problem, it creates a different one: higher energy bills.

Furnace Blower Motor

The furnace blower is a fan that delivers warm or cold air through the duct system of your home. The options include standard, high-efficiency, and variable speed.

  • Standard blower motor – These have three set speeds. Low for air circulation, middle to move heated air, and high to move cold air (from your air conditioner) through your ductwork.
  • High-efficiency blower motor – These are quieter and do not have set speeds. They ramp up and down depending on what speed is needed. They also do a better job of balancing the temperature and controlling airflow throughout the house.
  • Variable speed blower motor – These move at different speeds to precisely control the flow of air throughout the house. They are even quieter than high-efficiency motors as it runs in a lower setting the majority of the time. Even when the furnace is not turned on, the motor can be in constant operation, circulating air through the house.

The heating experts at Design Aire install all different types of furnace replacements. We can help you determine which furnace is the best fit for you and your home!

Furnace Installation and Replacement Add-On Services

In addition to our dependable furnace installation and replacement services, we also offer the following add-on service:

  • Two-Pipe Furnaces – Because of the tax credit, rebates, and a desire to improve their utility bills, many people are opting for high-efficiency furnaces. These 95% efficient units require a PVC flue because they remove so much heat from the gas that condensation is formed in the flue (the heat isn’t wasted on flue temperature, but is used to condition your home).

Every major manufacturer recommends installing these furnaces as a two-pipe system (a separate pipe for intake and exhaust) whenever possible in the furnace installation process. Although this practice requires additional labor, reputable HVAC contractors install two-pipe systems because it prevents depressurizing the house and pulling unconditioned air into the home.

Contact Us for Furnace Installation and Replacement

Contact your St. Louis HVAC company today to get a free estimate! With our professional heating installation and replacement services, your furnace can be up and running again in no time!

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Financing is provided with approved credit by Wells Fargo Bank, N.A., an Equal Housing Lender.
Design Aire offers special financing with approved credit with this secure application:

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Customer Testimonials

Seth was our salesperson. He listened to our needs and provided the right product at the right price. The installation team arrived on time and went right to work.They worked with confidence and professionalism.We appreciated the care in protecting our floors and even the choice of how they went up on the roof indicated that they really did care. This company did what they said they would and certainly has our vote of appreciation and gratitude. We will happily recommend Design Aire to anyone.

Ken L.

One of the best companies to work with. My own profession is in a service industry and so I very much appreciate all the positive things about Design Aire.
The install crew arrived right on time and took exactly how much time they said they would to complete the job. The work was done well, the crew cleaned up after themselves, and were very pleasant. Seth in the office was extremely in-tune to our needs and very responsive.
I would highly recommend Design Aire.

Heather H.

Our new HVAC system was installed yesterday and we could not be happier. From quote to completion the process was great! 100% would recommend!

Greg H.

We have used Design Aire for both a new furnace two years ago and a new AC unit this summer. Everything was done very professionally and quickly. I would not hesitate to recommend them to anyone needing any type of HVAC work done.

Sean K.

Design Aire was the best choice from start to finish. Design Aire gave me the best price with the most detailed quote. The service technicians were very friendly and completed the job ahead of time. I highly recommend Design Aire.

John K.

We've used them for our old house and our new house. They are honest, friendly, professional and affordable. We felt lucky to find them.

Maddy R.

I was very impressed with Design Aire. They were timely and did an outstanding job with the installation of my new furnace. They had great communication and went above and beyond. I would highly recommend them to friends and family. Thank you so much Seth and Design Aire for making this an effortless transaction. VERY PLEASED!

Jonny M.

Design Aire sent a salesman to plan the system, and just a couple of days later sent the installers to remove the old system and install the new one. Everything happened when they said it would and the system performs as they said it would. All of the Design Aire staff were courteous, the work was performed efficiently and neatly, and they left the area cleaner than they found it. This is the second unit Design Aire has installed for us, and I have no need to look elsewhere.

Dan L.

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