SOUTHEAST WISCONSIN’S HVAC EXPERTS

ESTABLISHED IN 1962

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 three generations strong and still follow the most basic rule of business: we treat our customers the way we want to be treated.

About Us

WHAT OUR CUSTOMERS ARE SAYING

Google Rating

4.9

Based on 827 reviews

Interstate Heating Co., Inc.

4.9

Jeana Holt

19:53 07 Oct 25

Tristen did a phenomenal job communicating with my husband and I throughout the HVAC system maintenance visit. He ensured that we both understood the implication of his recommendations and potential cost if/when we choose to have something repaired. I HIGHLY recommend Interstate Heating Co., there service always exceeds my expectations.

Aaron Holt

19:10 07 Oct 25

Tristan was awesome. Timely, thorough and great communication throughout!

Dennis Shebesta

15:45 07 Oct 25

Chris was the best guy we’ve had here from interstate in the last 25 years. Five star plus

William J Radler

10:59 05 Oct 25

Rod Myers

19:59 02 Oct 25

Friendly and efficient

James Spangler

19:07 02 Oct 25

He did a good job. Give him a raise.

Judy Stagl

18:26 02 Oct 25

David Beilfuss

17:02 02 Oct 25

John did a great job!

Karen Chamberlain

18:52 30 Sep 25

Excellent service. Knowledgeable and caring serviceman!!

Ronald Motley

11:15 30 Sep 25

Called Interstate on 9/24 for an estimate on a whole house humidifier replacement and an attic fan problem. They said they would email me an estimate. It’s 9/30 and not a peep. No follow-up from customer service to check on the quote status.Shows lack of respect for customers and poor internal processes.

Laura Staton

21:59 29 Sep 25

Dylan was great! Timely and very efficient. Thank you for your quick and friendly service!

John Nosbisch

13:40 28 Sep 25

Fall Update: Eric was back for our heating maintenance. He discovered a wearing component which would shut the system down due to safety. No one wants to be cold in January. Eric quickly replaced it avoiding a winter emergency service call. Great job Eric!Eric Osterman was recently to our home for our annual A/C system preventative maintenance. He was very professional, thorough and answered my questions in a manner I found easy to understand. The good news was Eric discovered and quickly replaced a key component in the outside compressor that would have eventually failed preventing the home from being cooled. That is the value of their preventative maintenance program. Thanks Eric!!!

Wes Breeden

20:53 26 Sep 25

The entire experience was very well completed, and I believed the pricing was extremely fair. Also, thanks to classic homes for the recommendation.

Bridget Post

19:59 26 Sep 25

Dylan was great and very knowledgeable!!

Jeff Guidinger

16:19 24 Sep 25

Laurie Kempke

16:34 23 Sep 25

The technician was polite and friendly. He explained the process and results. Would recommend to my friends.

Jocelyn Irvine

19:11 22 Sep 25

Casey A. was extremely professional, but also very personable. Will hire them again!

Scott Lucas

17:17 22 Sep 25

Thorough, professional work

Susan Gebauer

17:08 22 Sep 25

Bill Paquin

21:23 20 Sep 25

Great tech. Friendly and helpful

Kyle Behrens

22:46 17 Sep 25

Randy Moll

19:39 17 Sep 25

Service technician Tristan was on time, professional, and courteous. He did his job quickly and accurately. He detailed the work he performed, and cleaned up afterwards. I have used Interstate for many years ,and would recommend them to anyone needing this service.

Susan Yokosh

18:02 17 Sep 25

Michael Urban

22:44 12 Sep 25

Josh and Tristan did a great job of diagnosing our problem, communicating what needed to be done, and then providing the fix. We received outstanding same day service.

LINDA KAUTZ

00:16 12 Sep 25

Showed promptly. Checked various components and operations. Answered questions. He was very professional.

Edward Raether

12:58 11 Sep 25

Prompt response and excellent installation of new furnace

Peter Beardsley

01:00 10 Sep 25

Peter Diotte

18:18 09 Sep 25

Eric was the service tech - total pro - on time and performed the annual maintenance on the heating and A/C systems. We talked about upgrading existing thermostats to WiFi ones and he had the desired models onboard. In addition, we talked about a possible future garage heating unit install and talked me through it. I would rate service as Excellent.

Ildiko Huppertz

17:36 09 Sep 25

Chris was the ultimate professional. He repairs the miss wiring of another technician preventing me from having to replace my furnace. I am grateful for his honesty and service and now a future customer going forward. Interstate came highly recommended and it was spot on. Service call cost is the most reasonable of any other vendors.

Mary Jo Dempsey

15:11 08 Sep 25

David Schieszler

19:52 05 Sep 25

Good crews, fair price, timely installation of a new boiler. Happy with the service provided.

Debbi Triplett

14:03 04 Sep 25

Mark Treadaway

18:08 03 Sep 25

Prompt, clean, very professional. Explained what they were checking and what they found.

Mark Treadaway

18:05 03 Sep 25

Efficient, polite, and professional

Fred & Jane Lawler

18:00 03 Sep 25

Guys we’re very professional

Ms. Basquet

16:33 03 Sep 25

Texted before arriving. Very polite and professional. Explained everything. Both guys were very nice and respectful. Very happy with them.

Jonathan Dake

23:13 02 Sep 25

Suri Venkatraman

19:35 28 Aug 25

Joey Bohlmann

19:02 27 Aug 25

Good communication-explained everything well, efficient and thorough.

Lori Papa

12:49 26 Aug 25

Tristan and Joe were on time, very professional and informative.

Tony losiniecki

19:01 25 Aug 25

Chris is honest, professional and knowledgeable. Quick diagnosis of the issue. I highly recommend Interstate Service!

Alex Pitts

14:16 25 Aug 25

A fine young man. Very knowledgeable.

Jerome Pitts

20:18 22 Aug 25

Josh did a fine job. Confirmed system is operating correctly. Will probably sign on with Interstate maintenance program.

Jennifer Johnson

20:12 22 Aug 25

Melanie Bond

13:09 21 Aug 25

Tom Konkol

03:35 21 Aug 25

Josh was first class in every way. Helpful and to the point. I recommend him to anyone. Amen.

TOM KANTER

01:23 21 Aug 25

ExcellantKNOWLEDGABLE AND FRIENDLY

Joel Anthony

22:32 20 Aug 25

Dylan did a great job reassuring us that our furnace was in fine working order after a sub pump failure5 stars!

Andy Murphy

19:56 20 Aug 25

Knowledgeable and efficient.

Michelle O.

19:44 19 Aug 25

Dean Maytag

19:10 14 Aug 25

Excellent, the tech, Dylan, was very helpful and knowledgeable. Mask and booties much appreciated

Curt Nash

18:04 14 Aug 25

Brent Boettcher

14:31 14 Aug 25

Bruce Seefeldt

17:47 13 Aug 25

Tristian the technician was great, he diagnosed the problem, gave me options and completed the repair. He was very professional, friendly and kept me updated at all times.

Cindy Schaus

17:36 13 Aug 25

Josh is a careful professional that makes it all work!

Michael Reinders

12:08 13 Aug 25

Tristan came out to get our A/C back up and running. He went through the troubleshooting and kept me informed all along the way (I appreciate that!). He found the communication (wiring) between the two units was bad and ran a temp wire to make sure. Thankfully, the system started up. Then, he moved the wire to a safer location until someone else can come out and re-wire professionally.No issues! Tristan was very easy to work with and would recommend he come out for our next visit.Highly recommended! It was a pleasure doing business with Interstate again.

Brad Brogan

00:07 13 Aug 25

John Beauchamp

18:42 12 Aug 25

Tristan did an excellent job in diagnosing and repairing the air conditioner unit. Thank you for the great service!

kpbDO kpbDO

13:57 09 Aug 25

Great experience as always. The team was friendly, skilled and hard working. Always a pleasure working with Interstate from the scheduling to the HVAC team.

gert

16:15 08 Aug 25

Excellent service and communication. Thorough. Resolved problems quickly. Very pleasant and friendly.

Christine Jahncke

22:09 07 Aug 25

Tristan did an excellent job diagnosing the worn out part in my air conditioner and went above and beyond to get the part replaced the same day. Thanks Tristan for all your hard work!

James O'Laughlin

21:46 07 Aug 25

Very professional, always a pleasure working with their team.

Paul DeYoung

15:29 06 Aug 25

Chip Losee

18:47 04 Aug 25

Very satisfied, Tristan was awesome. Very professional and knowledgeable.

Steven P

15:28 04 Aug 25

Stephanie Chapman

05:40 03 Aug 25

Chris Carne was fabulous. He was very professional and knowledgable. He knew the product and taught us about new products as well. I would highly recommend Chris.Stephanie

Brian Riddle

01:45 02 Aug 25

Quickly found a time that fit my schedule. Received a call to see if the tech could come early. Very polite and professional. Found and fixed the air conditioner very quickly.

Jennifer Hirsch

14:14 31 Jul 25

Josh did a great job. He services our radiant floor

Elizabeth Noorlander

20:47 30 Jul 25

I’ve used Interstate for years. The whole team is super helpful and professional, prices are the best in the area. Dylan fixed the issue quickly and explained what was happening. I had to leave to pick up my son, and Dylan even took the time to ask if his car was ok.

Sheri McNabb

19:45 30 Jul 25

Very professional, courteous and efficient

Adam Schlichting

18:35 30 Jul 25

lana kuenzi

16:57 29 Jul 25

Showed up on time, very professional, courteous & clean

kim mangarelli

18:19 25 Jul 25

Pat Miller

17:58 25 Jul 25

Karen Barnes

20:43 24 Jul 25

Josh was able to answer a reoccurring message that I have received multiple times on my thermostat.

Fred Kinateder

19:45 24 Jul 25

Josh did a great job. I was very satisfied with the service. He also gave me some suggestions as to my options for repair or replacement.

Scott Morey

17:15 24 Jul 25

Quick response with a fast diagnosis and repair for my HVAC system.

Kristine Cherek

11:02 24 Jul 25

Interstate Heating is exceptional. Our technician Chris was very professional, proficient, and friendly. I highly recommend!

Jerry Kienast

18:29 23 Jul 25

Josh was an honest tech and did a great job! I would highly recommend.

John Krainer

17:43 23 Jul 25

Very professional and courteous.

Sa Gt

16:20 23 Jul 25

Our technician Chris was extremely knowledgeable and courteous!!!

Dan Mishich

14:26 23 Jul 25

We had the pleasure of working with Jake on short notice while preparing to sell our home. He quickly familiarized himself with our in-floor heating system, reviewed the setup for accuracy, and performed thorough thermal scans of the floor. His deep knowledge and clear communication helped put our buyers at ease and addressed all of their questions. While no repairs or service were ultimately needed, I wouldn’t hesitate to recommend Jake—his expertise in these complex systems is rare and incredibly valuable.

Robert Schmidt

01:14 22 Jul 25

debbie grannan

23:52 21 Jul 25

Chris was very friendly and knowledgeable, looked at the thermostat readings and knew right away what the problem was.Only took about 15 minutes

Jeff Katzer

21:54 21 Jul 25

The technician was on time and very helpful. Diagnosed and repaired issue within an hour. Will recommend company to others.

Michael Ford

14:32 21 Jul 25

Chris is helpful. Explains his findings in detail and is also courteous. We give him 5 stars!

Lucky An!erson

14:06 19 Jul 25

It took forever to finish the job. He was concerned about getting paid.

Lisa Cretens

20:03 18 Jul 25

Our experience with interstate heating is always top notch. Our tech was very informative.

Gregory Harris

19:42 18 Jul 25

My issue was a simple fix. The evaporator coil drain elbow was plugged causing the water tray to over flow and cause water to leak on top of the furnace and floor. What was exceptional about the service was the technician (Eric) took the time and showed me how to address the issue in the future on my own. He even took the time to take the evaporator panel off (3 screws) and explain how the system works and where the tray was. Eric’s care in teaching me was outstanding. Great customer service by Eric!

rick worzala

23:12 17 Jul 25

Amanda Hetzel

13:47 17 Jul 25

Amazing service! Technician was very polite and knowledgeable! Couldn't ask for better service!

The games god Games among you

13:38 17 Jul 25

New AC unit and furnace installed by a great crew.

Cindy Macaluso

20:44 16 Jul 25

Interstate came to the rescue almost immediately. Hopefully our house will be completely restored to a comfortable temperature by this evening. Dylan was very nice and answered all of our questions. Highly recommend this company. The woman that answered my initial call was very nice and helpful.

Pamela Probst

13:34 16 Jul 25

Eric was friendly, efficient, and professional. He explained what needed to be fixed and why while completing our check-up maintenance on our heating/cooling systems.

Francisco Quiroz

12:43 16 Jul 25

Erik did a great work with our AC Unit. He took the time to do what was a difficult job and our unit was like new when he finished. Thank you

Matthew Mascal

20:35 15 Jul 25

Lauren Roberts

19:56 15 Jul 25

Tristan was an excellent serviceman. The customer service at the office was always helpful, kind and polite. Highly recommend!

Randy Will

16:40 11 Jul 25

Discovered my old thermostat control was inoperative. Called Interstate & got immediate response to my problem, had a tech at my home within 2.5 hours - on a Friday afternoon!!Excellent service & attitude from Jennifer, the dispatcher.Eric, the service tech, was considerate, knowledgeable, professional & patient.

David Smith

03:35 11 Jul 25

Great

Linda Froehlich

18:46 10 Jul 25

Josh did an A plus job. He was considerate & I have gratitude that he went & got the parts & finished the repair instead of coming back the next day. Excellent !

See all reviews Write a review

“Eric, John and Carson were all phenomenal with the replacement of my 20-year-old AC unit. Communication and work ethic were awesome. Thank you!”

- Amy K.

“Dylan did a great job for us. We asked for the yearly maint on the AC, Heating, and Humidifer. everythign went smooth and he answered any questions we had.”

- Gary S.