Heating FAQs

When it comes to furnace repair, maintenance, and replacement, there’s a lot to know. Below are some of the most frequently asked questions our Design Aire technicians answer regularly. Got questions? Ask the pros at Design Aire!

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How many years does a furnace last?

A well-maintained furnace usually lasts anywhere from 12 to 18 years before it needs to be replaced.

What size furnace do I need?

The size of the furnace you need depends on a number of factors—not only the square footage of your home. In general, you’ll need 25 to 30 BTUs of heat per square foot to heat a home with standard insulation in a moderate climate. However, our Design Aire professionals take into account your home size, the local climate, your insulation, and your lifestyle, among other factors, to better estimate what size furnace will work best to keep you warm.

When should I replace my furnace?

A good rule of thumb is that, when the cost to repair your furnace gets to be half the cost of replacing it, then it’s time for a new furnace. An even better rule of thumb is that, when your trusted HVAC company tells you that your furnace is becoming less energy efficient, or that problems with your furnace are beyond simple fixes, it’s time to consider installing a new furnace. Our Design Aire professionals will never recommend something they wouldn’t do themselves, and we know the importance of saving you money. When it’s time, financing is available and we will do all we can to make your furnace installation as efficient, fast, and cost-effective as possible.

Will a new furnace save me money?

If you truly need a new furnace, chances are good that a newer model will be considerably more energy-efficient, meaning it will cost less to run than older models. In addition, you’ll likely save money on repair bills for a newer furnace. Your Design Aire professional will ensure that the furnace you purchase is the right size for the job, creating cost-effective comfort your whole family can enjoy.

How often do I need to maintain my furnace?

An ounce of prevention is worth a pound of cure—and a whole lot of money saved on repairs, when it comes to your furnace. We recommend service calls to maintain your heating system twice a year, and Design Aire offers hassle-free furnace maintenance plans to help you out.

How often do I change my filter?

Most filters need to be changed about every three months, but they should be changed more frequently if they are visibly dirty.

When should I call for repairs?

If your furnace is regularly maintained, chances are good that you won’t need to call for repairs. That’s because our Design Aire technicians are exceptionally good at identifying issues before they become a problem. However, if any of the following problems occur, call us right away:

  • The ignition light on your furnace is not functioning.
  • Your flame sensor is not working.
  • The motor is making noises.
  • Your thermostat is blank or does not appear to be functioning.
  • Your furnace is cycling off and on too frequently.

Can I maintain my furnace myself?

Unfortunately, a little bit of knowledge does not always go a long way. Your furnace—and your entire HVAC system—is a significant investment, and do-it-yourself repairs can often cause more harm than good. Things you can do, however, include:

  • Replace your filters every three months, or sooner if they are noticeably dirty.
  • Keep your furnace and the area surrounding it free of dirt and debris. Be sure laundry or other clutter does not pile up around it, and keep the area clean.

When you need HVAC repairs, maintenance, or replacement, Design Aire is here for you. Give us a call, and our fast and friendly licensed and insured technicians will be there to keep your home warm in the chilly winter months!

Need Furnace Repair? St. Louis & St. Charles, MO Trusts Design Aire

Let Design Aire do what we do best. Improper furnace repairs can pose gas- or combustion-related safety hazards, so leave your troubleshooting to our trained and expert team of furnace repair specialists. For over 100 years, we have established a proven record of honesty, integrity, and excellence.   

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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.