Gas Furnaces

Furnace service.

Interstate Heating Co. is the leading HVAC company in Sussex, WI, for your furnace service needs. We service and repair all makes and models. If you need furnace service, we are the company to call. Our skilled technicians are qualified to solve just about any repair or installation that you throw at us.

How Much Money Can a New Furnace Save You?

Our AFUE energy savings calculator can help determine how much you could save on your utility bills. Simply enter your current unit's AFUE value and compare it to a newer, more efficient system. You can even customize it to better match your home's system for a more accurate calculation.

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Furnace Repair

Don’t get left in the cold! Is your furnace acting up, blowing cold air, or making too much noise? Our experienced team of professionals is here to keep your home warm and cozy. We repair all makes and models, and we will never try to sell you a service that you don’t need. Our technicians are honest and hard working, and we’re always transparent and fair about the work we do.

Furnace Replacement

Sometimes a repair is not sufficient to fix your furnace. Sometimes a new furnace is the most cost-effective and energy-efficient way to go. We will always be honest with you about a possible furnace replacement. We value our time and your money––we don’t want to perform repairs or service on an appliance that is in need of replacement.

If you do need a furnace replacement, we know how overwhelming it can be. Here are some of the frequently asked questions about furnaces that we get from some of our Sussex, WI residents:

What Are The Different Types Of Furnaces?

Single Stage: A single-stage furnace has only one stage of operation. It can either be turned on or turned off.

Two Stage: A two-stage furnace has two settings––full and half speed. This is a more efficient way to heat and provides for better comfort, because it can move the air at a slower pace.

Variable Stage or Modulating: A variable-stage or modulating furnace modulates the speed and heat output based on the temperature outside and the desired comfort level. This furnace only works as much as you need it, making this type the most energy-efficient type of furnace.

What Is AFUE?

AFUE, or Annualized Fuel Utilization Efficiency, is a measure of furnace-heating efficiency. The higher the AFUE, the more efficient the furnace.

What Size Furnace Do I Need?

We can calculate the correct size furnace for your home. The number of BTUs, or British Thermal Units, needed to heat your home is dependent on a number of variables. Contrary to what you might think, a bigger furnace may not necessarily mean more heating power for your home. Call us at Interstate Heating Co., and we can set up an appointment to calculate the furnace size you might need.

Furnace and Air Conditioner Installation

I just wanted to drop you a quick note to say thanks for all of your efforts in getting us our new furnace and air conditioner—the installation crew did a fantastic job. I’ve shown a few people the installation and they were amazed at the neat, professional job that was done. Plus, the whole crew was very friendly and patient with me and my endless questions. The system is working beautifully. As you suspected, the temperature difference between the upstairs and downstairs has almost completely disappeared, and everything is so quiet you can hardly tell it’s on. I’m almost excited to get my next electric bill to see how much money we’ll save. We literally could not be happier with the system. I’m sure there are more exciting home improvements, but this necessity has given us the most benefit and a lot of enjoyment. I will highly recommend you and Interstate to anyone who’s in the market for new HVAC equipment, starting with my dad, who has a furnace and air conditioner that are nearly 20 years old. Thanks again. -Pete

Furnace and Air Conditioning System Installation

Your company recently installed a new Carrier® furnace and air conditioning system in our home. We were very pleased with the quality of service we received. From David, who oversaw the project, to the entire team helping with this installation, we were most impressed. Everyone was professional, knowledgeable, and extremely courteous, and did an excellent clean-up job when done. The entire job was completed in one day. This is one of the most satisfactory contractor experiences we have had. We will not hesitate to recommend Interstate Heating whenever the occasion arises. -Phillip R.

Heating & Air Conditioning System Installation

Your installers were top notch and your company did everything they said they would. I have received my rebates and was glad that your company made it so easy to get them. I will highly recommend your company to anyone I know who needs new heating or air-conditioning equipment. -Tim H.

Heating & Cooling System Installation

I have been a customer of Interstate for many, many years—I think I bought my first system from you in the late 80s or early 90s. You have an awesome company with awesome people working for you. I especially wanted to compliment your team because I have called twice since last week’s installation and am so appreciative of all the people I have worked with—I hope they do not feel I am being a bother. I have always recommended Interstate to anyone looking for heating or cooling solutions, and I just wanted to thank you and the entire Interstate group of people for being so good at what you do. Thank you so much and please let the people who worked on my systems in the past week know that. -Anthony

Furnace Installation

I just wanted to let you and Interstate Heating know that the crew you sent to do my furnace install did a fantastic job. They were very prompt and quick, did a professional job, and really seemed to be enjoying their work. On a scale of one to 10, I would give them a “10”. And this new furnace is really quiet—what a nice change compared to my old one. -John H.

Need Furnace Service?

Contact the experts at Interstate Heating Co.

Call us at 262-246-4772!