Get Quotes Contact Us Sign In
Website
Call
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.
Services
What began in a garage in 1962-with Gordon 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.
Furnaces and air conditioners can provide years of comfort for your home or business when you have routine maintenance performed. Maintenance is the key to reliable operation and fewer repairs, so don't wait until your system has a complete breakdown to call Interstate Heating Co. We're experts at installing heating and cooling systems, but we're also the area's best HVAC maintenance and repair team. We believe in preventing problems-not just fixing them. So we offer maintenance agreements that make it easy to plan and pay for ongoing service.
According to the U.S. Department of Energy's Energy Star program, leaky ducts in attics or crawlspaces can account for 20 percent or more of a home's heating and cooling energy losses. This results in higher utility bills for you and difficulty keeping your house comfortable. Run your system, and check all the ducts and joints you can access.
Most people immediately think of furnaces when opting to heat their homes. However, boilers provide a highly effective heat option, have a long life, can reach high heating efficiencies, and some types require little or no pumping energy. Boilers are an important part of a central heating system. They're a continuous closed loop of pipes carrying heated water (or steam) throughout your home.
Reviews (10)
Write a Review
Don Mantz
Jun 28, 2022
I thought we would have to wait days to have our AC fixed. I called on Saturday and had a tech at the house 10:30am Monday. He had it repaired in an hour. Eric knows what he's doing. Very professional. Service: A/C system repair
Scott Olds
Jun 25, 2022
Kevin was very professional and figured out what wrong very quickly. Interstate is a class act and I would call them again, now questions asked. Thanks Kevin!
William Wright
Jun 13, 2022
Very receptive to our needs. Excellent work and very honest. They have the best service and personnel in the entire area. Services: A/C system maintenance, A/C system repair
Tim Dewar
Jun 12, 2022
Service tech was on time and very professional. Was very efficent on his diagnosis and repair. A big thumbs up to Ethan L. for his work. Service: Repair HVAC
Anna Coufal
Jun 11, 2022
Critical: Quality, Value Will never use this company again. Came out to possibly repair my AC unit and was told I need to spend $5450 on a whole new unit. Called another company for a second estimate and they fixed my AC unit for $300 dollars. Services: HVAC system maintenance, Repair HVAC
Mary Patricia Ceille
May 25, 2022
Diagnosed the problem extremely quickly. He was through polite and fixed it very rapidly. He It outlined our options for maintenance and in the future. We were overall very very pleased with this technician. Thank you Service: A/C system repair
Scott Burns
May 07, 2022
I have had great service from Interstate Heating and in particular Eric Osterman. Eric is one of those guys that is a straight shooter and he really knows his stuff. He serviced our furnace this last winter and rather than just fix what was not working he replace several things that were warranty items and for the first time in 7 years the heat was better than we new it could be.

Just had him out to look at the AC and again took care of the small issue showed me how to keep thing in great working order. I ask for him even if I have to wait, thats how much he has my trust.
Dan Habeck
Jan 24, 2022
I had used Interstate for my general residential HVAC service and contacted them about the installation for a basement build-out. They were a one stop solution for everything I needed and the process was seamless from estimating to contracting to rough install to final install. We had a bit of a curveball with integrating with my existing technology and Interstate went above and beyond to solve the problem, including working with the manufacturer. I had a great experience and highly recommend Interstate.
Phil Mydlach
Nov 19, 2021
We have used Interstate Heating for the last 15 years and have never been disappointed with their service. Their technicians are professional, friendly and explain things in simple terms. Everyone from dispatch, reception and technical have been terrific to work with. Service: Heating system maintenance
Mary Piekarski
Feb 25, 2019
Interstate installed our vents, furnace and air at our new construction home. The initial installation went fine - but then we noticed that our bathroom vents had Tyvek paper covering the exhaust screens at the roof - so they had to come back to remove that. It was restricting air flow making the bathroom vents not function properly. Another thing they didn't do when they installed the furnace and ductwork was they did not cushion the vents so simply walking upstairs above where the ductwork was located made a screechy metal on metal sound.

They had to come back to install rubber cushioning material and that eliminated that issue. Now, the new cooing season is upon us. We called another time because the A-Coil inside the furnace got completely frozen solid in spite of our changing our furnace filter constantly. Then they had to come back again because the blower wasn't functioning properly, they replaced a part.

That's working again. So since those last site visits, the plenum has been covered with condensation and we get water all over the floor from the condensation. I have been wiping the unit down almost daily. The housing for the furnace is starting to rust from all the condensation and you can feel the cool air between the housing and the plenum leaking out into the basement.

One of their own contractors mentioned that it appear as though the installation crew didn't put a gasket in that area, so that's why he thought we were getting leaking air and condensation. But he couldn't fix it because that's the installation crew's job. So now we're trying to get the installation crew to come out an put that gasket in so that we don't have to have condensation running all over onto the floor and into the joint where the furnace housing meets the ductwork.

My husband has called no less than 4 times, asking for someone to call him back to get this gasket installed. There is never anyone at the office number to talk to - just some woman who doesn't know anything. He even asked for the manager's number and left that guy a message and asked him to return his call. NO BODY has returned any of his calls and we are furious!

How many times does a consumer have to contact a service provider before they get someone to help them? I would lay you bets that they keep avoiding us until such time that the equipment's one year warranty expires and they will charge us to fix all the things that they should have done right in the first place.