Interstate Heating Co., Inc.

Interstate Heating Co., Inc. has kept southeastern Wisconsin warm since 1962, when Gordy and John Cole started the business in a garage with a simple mission: treat customers the way they wanted to be treated. Now three generations strong, this Sussex-based contractor operates around the clock, every day of the year, and has grown to serve the entire southeast Wisconsin region. The company holds a 4.9-star rating from 959 Google reviews, placing it among the most reviewed and highest-rated HVAC contractors in the Milwaukee metro area. Whether you are in Sussex, Waukesha, Brookfield, or one of the neighboring communities, Interstate's fleet of service vehicles responds to both emergency calls and scheduled maintenance appointments.

What distinguishes Interstate Heating from regional competitors is their Carrier dealership and their comprehensive range of heating and cooling solutions. As a Carrier authorized dealer, they install and service the full line of Carrier equipment, including cold-climate heat pumps, high-efficiency gas furnaces, geothermal systems, and mini-split ductless units. The company also handles radiant floor heating, boiler systems, snowmelt installations, and dual-fuel setups for homes seeking optimized energy performance. Their in-house sheet metal fabrication capabilities allow for custom ductwork, and their CoolCARE warranty program offers ongoing protection for installed equipment.

Customers repeatedly highlight specific technicians who go beyond standard service calls. Eric has earned multiple shout-outs for thorough explanations and professional demeanor, with one reviewer noting his ability to diagnose issues quickly while treating the home with care. Chris has been described as a tremendous representative of the company, arriving on time and keeping homeowners informed throughout the diagnostic process. When a customer's new furnace developed a leaking gasket, technician Tristan responded promptly, answered all questions patiently, and ensured the repair was completed correctly. These named interactions illustrate why Interstate maintains such a strong review profile despite occasional concerns about pricing.