Scenic Small Town Nestled Amid Fertile Valley In Beautiful Rural Wisconsin.

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HEATING and COOLING

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.

RADIANT HEATING

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!

INDOOR AIR QUALITY

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.

SHEET METAL ROOFING

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.

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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.

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

“We were very satisfied with the prompt response and service from Interstate, and especially Eric who came to our house and replaced the capacitor in our air condition compressor. He was very personable and courteous and he seemed to know what to look for and quickly replaced the capacitor. We would highly recommend him and Interstate to our relatives, friends and associates.”
- Joseph K.
“Two service technicians came on time and replaced the secondary heat exchanger in little over two hours. They were efficient and courteous. I have had Interstate do maintenance on my furnace and A/C for over 13 years. They are fair and upfront with pricing and any component failures. I would and have recommended them to my friends.”
- Robert W.
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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.

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Ductless Mini Splits for Comfortable and Healthy Living. Flower arrangement on an end table.

Ductless Mini Splits for Comfortable and Healthy Living

August 29, 2024
Fortunately, ductless mini splits can provide all the essentials for home comfort—warm air, cool air, ventilation, and humidity control. Plus, they’re much more efficient than a standard air conditioner and furnace combination. Read More
Why Air Conditioners Freeze Up. Frozen AC units.

Why Air Conditioners Freeze Up

August 15, 2024
Did you accidentally stumble upon your air conditioning (AC) unit’s “winter weather” setting? Nope. You’re probably experiencing a freeze up. Read More
Man cleaning air ducts in home.

Air Duct Cleaning

July 29, 2024
Your air ducts circulate a supply of fresh and properly treated air. But since ductwork mostly hides behind walls, ceilings, and floors, many Wisconsin homeowners don’t take the time to monitor its condition. Read More