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When it comes to your comfort, our Interstate Heating Co. professionals are experts. Our team is trained, certified, and ready to take care of whatever your HVAC needs may be.


The installation of radiant floor heat costs more initially than more conventional heating systems, but in the long run, it saves money due to lower thermostat settings and higher efficiency. Call Interstate Heating Co. to schedule a quote today!


Your indoor air quality (IAQ) is central to your health and comfort. Enjoy a breath of fresh air and allow our team to find solutions that improve the air quality at your home or business. Let us help keep you safe and comfortable.


Call Interstate Heating Co. to speak with one of our certified technicians about how a sheet metal fabricated roof can be a durable, cost-effective, and on-demand solution for you.

Our Story

Continuing a Tradition of Exceptional Heating and Cooling Services

What began in a garage in 1962—with Gordy and John Cole’s commitment to offering honest, high quality HVAC service—continues today at Interstate Heating Co. in Sussex. We’ve grown to offer the latest heating, cooling, and air quality products, and our service area now covers all of southeastern Wisconsin.


We Are a Carrier Factory

Authorized Dealer

Carrier Factory Authorized Dealers work hard for this designation. And all their experience and work is for one purpose—to create comfortable homes and satisfied customers. So when you need a new system, or it’s time to service or repair your current equipment, you can trust you’re working with the best in the business.


We love hearing from our customers! If you’ve had us work on your HVAC system we would love to hear from you too.

Gas Furnace Repair in Mequon, 53092

“Very easy to work with. Quick response and very professional. I would highly recommend.”
- Suzanne C.

Gas Furnace Maintenance in Waukesha, 53149

“Thank you Ethan for your excellent, friendly service!”
- John B.

Gas Furnace Repair in Pewaukee, 53072

“Technician diagnosed the problem, ordered a replacement part, and then a different technician came back to install the part after it came in. The furnace is now working properly. Thank you Jason and Kevin.”
- Robert L.

Three Generations Strong

After all this time, we still follow the most basic rule of business: we treat our customers the way we want to be treated. And we know that comfort is a big part of what makes a house a home, so we make it easier to create and care for an ideal environment.

Video - Keep Clean Air During Your Time at Home. Image is an animation created in shades of purple and green. There is a woman on a couch reading a book and a man sitting next to her looking out a window. On the ground in front of them there is a small girl laying on her belling and drawing on a piece of paper.

Video – Keep Clean Air During Your Time at Home 

March 22, 2023
Keeping clean air circulating your home is very especially important due to more time spent at home. Contact us today for more information. Read More
Image of someone working on a furnace. Why Won't My Furnace Stop Running?

Why Won’t My Furnace Stop Running?

March 8, 2023
Is your furnace blowing air without pause? If so, you’re probably feeling a bit concerned. Read More
Image of a home. Video - Which Air Quality Equipment Should I Install?

Video – Which Air Quality Equipment Should I Install?

February 22, 2023
Indoor air quality is on everyone’s mind but how do you know what equipment is right for your home? Read More