The Process of Installing a New Furnace

To understand the process of installing a new furnace, you’ll first need to know how a furnace works, which is simpler than you think. Still, always remember that you should hire a professional to install your furnace for you.

Here’s how a furnace works. A natural gas furnace is connected to an existing return duct from which the air in your house (which is cold) flows through the furnace. Once inside the furnace—which is supplied with heating energy through natural gas—the air is heated and pushed out through an existing supply duct to warm your home. The process is quite similar for an electric heater except that the heating system is powered by electricity.

What Happens During a Furnace Installation in Chicago?

Installing a furnace—while you shouldn’t attempt it yourself—is simple, at least in concept. You just need to connect the furnace to the existing ducts so that the air can flow in and out of the furnace. Then, you need to connect the furnace to your home’s gas line and electricity. Again, working with your gas line can be very dangerous if you’re not trained to remove furnaces, so make sure to call for professional furnace installation in Chicago.

All that said, installing a furnace becomes a great deal more complicated if the furnace you’re installing is larger or smaller than the previous one. Often times, furnace installers will need to extend or redirect ducts, gas lines, or electricity lines. This makes the furnace installation process more complex, which is why some jobs may last as few as 4 hours and others may take a whole day.

The Furnace Installation Process at Deljo Heating, Cooling & Plumbing

The furnace installation process at Deljo Heating, Cooling & Plumbing is easy on you. We help you find out what type of furnace to install—which is extremely important, both for your comfort and for your energy bill. We’ll consider everything when choosing your furnace, from the age of your home to the size of your window.

That way, we can provide just the right amount of heat that you’ll need to stay comfortable even during a Chicago winter.

Call Deljo Heating, Cooling & Plumbing Today

Do you need a furnace installation in Chicago completed? Give the experts at Deljo Heating, Cooling & Plumbing a call at 773-829-4295. We’ll provide a free, no-obligation estimate. And, when you choose us, you can count on our passion for quality work and outstanding personal service from the moment you place your call.

Our Service Areas

Contact Deljo Heating, Cooling & Plumbing today. We look forward to hearing from you and helping out with all your indoor comfort needs.

Client Testimonials

Read the opinions of our satisfied customers.

Call Now 773-280-8251 Schedule Your Service

This was my first time as a Deljo customer, and I was very pleased. My technician, Giovanni, was very thorough and diligent. He serviced my furnace and identified a faulty sensor that was causing the unit to shut itself down. Deljo ordered the part, and Giovanni replaced it a few days later. Overall, the team at Deljo was great. The dispatcher kept me informed about Giovanni’s arrival time, and the supervisor assisted Giovanni when he was diagnosing the problem with the furnace. I highly recommend Deljo.

Paul D. 10/15/2026

I’ve used Deljo for over 10 years now and they always do a good job. Izzy was the technician for this visit and he did an excellent job with my winter maintenance on my multiple units in the household. He also addressed an issue while cleaning the furnace blower wheel. His communication was clear and concise with what he planned to do to address the issue quickly. He was confident and I had 0 concerns or questions. Great job Izzy!

Jeff S. 10/14/2026

Paul was great! Arrived on time and completed maintenance on my humidifier, tankless water heater, and two furnaces. All work was performed under my Gold Star maintenance program, so all maintenance charges were covered. Paul did provide a few proposals for additional services on furnace & tankless water heater, but those were emailed to me for further consideration. Paul was friendly, knowledgeable, and answered all my questions.

Jack N. 10/12/2026

Gabe did an excellent job with our annual service visit. He arrived in the early part of our service window, was friendly and knowledgeable, and got the work done in a very reasonable amount of time. I have great confidence in Deljo, and am a long-time customer.

Ruth C. 10/9/2026

I’ve been using Deljo for 20 years for HVAC but now venture into enlisting their plumbing services. Bashar was very courteous, efficient & informative, and I’d definitely request him again for the next plumbing job. Great experience!

Christopher R. 10/2/2026

Working with Deljo is always a good experience, and today’s appointment with Izzy was no different. He was able to come early which actually worked better with our schedules, but called me ahead of time to make sure that was okay. He was friendly and knowledgeable when he explained the work he had done during his visit and our options for fixes. He was also able to schedule a quote appointment for us while he was still here. We would highly recommend working with Izzy and the Deljo team!

Lauren H. 9/25/2026

Drew performed the seasonal maintenance on my AC. It needed some repairs and updates and he was able to fix everything at the same appointment. He also noticed issues with the hot water heater and we were able to get ahead of that, as well.

Emily W. 9/11/2026

I would leave six out of five stars if I could! My technician Jorge went above and beyond on his service. There was buildup in the rental property’s toilet from the previous tenant. One maintenance person did a surface level job of cleaning but did not fully remove the obstruction. Jorge went above and beyond and came to a solution and even explained the perpetual problems older toilet models can cause. Moving forward with this insight, I can perform my own upkeep the previous tenant did not. Thank you kindly!

Kayla K. 9/15/2026

We just had our new boiler installed by Jonathan and Carlos. First rate work! They arrived on time, removed the old boiler, installed the new unit, and explained the features. Both guys were pleasant. Bring on the cold this winter! We are ready thanks to the team from Deljo.

Edward B. 6/26/2026

Deljo’s heating and cooling team was awesome to work with. As a first-time homeowner, I really appreciated how clearly they explained everything and answered all my questions. From the quote to the install and follow-up, the service was top-notch. Highly recommend!

Lindsey A. Chicago, IL

Matt did an amazing job. He serviced our home and our rental property. He gave us options to help our systems run more efficiently. He also told us about Deljo’s new plumbing inspection which was very affordable. He is great!

Jordan R. Chicago, IL

We had a problem with our Humidifier and called Deljo. Jesus came out to help and was amazing. He was extremely knowledgeable, detail oriented, and super courteous. Amazing customer experience!

Jeff C. Chicago, IL

Jordan and Jesus were extremely helpful and knowledgeable! We would 100% work with them and have them back. They were both very professional and efficiently fixed our heating system.

Emily L. Chicago, IL

Shout out to Ernesto for coming out and servicing our furnace and air con. Deljo provides a great service and glad to trust them with our HVAC for our small business.

Lauren H. Chicago, IL