Furnace Replacement / Installation

Gas Furnace Replacement & Installation in Highlands Ranch

Upgrade your home’s heating with our professional gas furnace replacement and installation services. We provide expert guidance and quality installation to ensure your new furnace operates efficiently and effectively, keeping your home warm for years to come.

Preventive Care

Expert Consultation

We help you choose the right furnace for your home, considering efficiency, size, and budget to ensure optimal comfort.

Energy Efficient

Seamless Installation

Our certified technicians handle the entire installation process with precision, ensuring your new furnace runs smoothly from day one.

Fireside Heating & Cooling
Gas Furnace Repair Highlands Ranch CO
Gas Furnace Installation Services Highlands Ranch CO
Emergency Furnace Repair Highlands Ranch CO

Warmth That Lasts

Furnace Installation & Replacement in Highlands Ranch, CO

When Your Furnace Goes, So Does Your Comfort

Here’s something I’ve seen play out more times than I can count. A homeowner notices their furnace is struggling in October. They decide to wait and see. Then February hits, the temperature drops to single digits overnight, and the system quits completely. Now they’re dealing with an emergency replacement in the middle of the coldest stretch of the year, with limited scheduling options and no time to compare equipment.

That’s the situation we’d rather help you avoid.

At Fireside Heating & Cooling, we’ve been handling furnace replacement and installation in Highlands Ranch for over 11 years. We’re locally owned, veteran owned, and we’ve built this business on the kind of straightforward service that actually earns referrals. No pressure tactics, no vague estimates, no surprises on the invoice.

If your furnace is aging or starting to show cracks, now is the time to have a real conversation about it.

Our Furnace Installation Services

New Furnace Installation
Whether you’re replacing a failing unit or installing a furnace in a home that previously relied on another heating source, we handle the full process from start to finish. That means removing the old equipment, preparing the space, installing and connecting the new system, testing every component, and walking you through how it operates before we leave.

We install high-quality equipment from trusted brands including American Standard and Trane, and we back every installation with a warranty so you have protection beyond just the day we finish the job.

Furnace Replacement

Furnace replacement isn’t just swapping one box for another. The new unit needs to be properly sized for your home, matched to your existing ductwork, and configured for your specific venting and gas line setup. An oversized furnace short-cycles and wears out faster. An undersized one runs constantly and never quite gets the job done. We do this right the first time.

Gas Furnace Installation

Natural gas furnaces remain the most common and cost-effective heating choice for Highlands Ranch homes. Modern natural gas furnace models have AFUE ratings of 80 to 98 percent, meaning far more of the fuel you pay for actually converts to heat. We help you find the right efficiency tier based on your home’s insulation, your energy goals, and your budget.

Heat Pump Systems

Heat pumps have become a genuinely compelling option for Front Range homeowners, particularly those looking to reduce reliance on natural gas or improve overall energy efficiency. We install and service heat pump systems and can walk you through how they compare to a traditional gas furnace for your specific situation.

Thermostat Installation and Upgrades

A new furnace paired with an outdated thermostat is a missed opportunity. Smart thermostats improve comfort, reduce energy waste, and give you better control over your system remotely. We install and configure thermostat upgrades as part of any furnace installation.

Ductwork Assessment and Repair

A new furnace pushing air through leaky or undersized ductwork won’t perform the way it should. We inspect ductwork as part of our installation process and address any airflow issues before they undermine your new system’s efficiency.

Why Highlands Ranch Homeowners Replace Before Winter

The Front Range winters are not gentle. Highlands Ranch sees extended cold stretches where temperatures drop well below freezing for days at a time, and a furnace that’s on its last legs will choose the worst possible moment to give out completely.

Furnaces generally have a lifespan of 15 to 20 years with proper furnace maintenance. Once a system crosses that threshold, or starts requiring frequent repairs, the math usually tilts toward replacement. You’re no longer fixing something healthy. You’re extending the life of a system that’s already in decline, one repair at a time.

The signs worth paying attention to include rising heating bills without a change in usage, uneven heat distribution throughout the house, unusual sounds during operation, visible cracks in the heat exchanger, carbon monoxide detector alerts, and a system that requires repeated service calls in a single season.

Replacing in fall, before you need the system daily, gives you time to choose equipment thoughtfully and schedule at your convenience rather than scrambling during a cold snap.

What Goes Into a Furnace Installation

A professional furnace installation involves more than most homeowners expect. Here’s what the process actually looks like when it’s done correctly.

We start with a load calculation to determine the right system size for your home. Square footage is only part of the picture. Ceiling height, insulation values, window area, and ductwork condition all factor into what your home actually needs from a heating system.

From there we handle equipment selection, removal of the old unit, new system installation, gas line connections, venting configuration, condensate drain setup on high-efficiency systems, thermostat wiring, and a full operational test before we consider the job complete. Most installations wrap up in a single day.

We also offer flexible financing with no money down for qualified customers, because a furnace replacement is a significant investment and the timing isn’t always convenient.

What Sets Us Apart

Why Choose Fireside Heating & Cooling?

Same Day Services

Same-Day & After-Hours Service

Enjoy prompt HVAC solutions with our same-day and after-hours availability.

Locally Own

Locally & Veteran-Owned

Proudly serving Highlands Ranch as a locally and veteran-owned business.

Payment

Convenient Payment Options

We accept all major credit cards for a hassle-free payment experience.

Customer Satisfaction

100% Satisfaction Guarantee

Your satisfaction is our top priority—guaranteed every time.

Honest Service

Honest & Reliable Service

Count on us for trustworthy and dependable HVAC services.

Finance

Flexible Financing Options

Get HVAC services with no money down and affordable monthly payments.

Local Expertise

Over 11 Years of Expertise

Benefit from our extensive experience in delivering top-notch HVAC solutions.

Licence

Fully Licensed & Insured

Rest easy knowing our team is fully licensed and insured for your protection.

Testimonials

What Our Clients Say?

Our commitment to exceptional service has earned us the trust and satisfaction of countless customers in Highlands Ranch and beyond. Don’t just take our word for it—see why so many homeowners rely on us for their HVAC needs.
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Meg Reinis profile picture
Meg Reinis
Google star 1Google star 2Google star 3Google star 4Google star 5
Nixon is smart and quick and honest and kind. He did exactly what he said he would do and quickly assessed the issue and knew exactly how to fix it. His pricing is great and I will use him every time. Best AC company I have found. Hands down.
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John Sepich profile picture
John Sepich
Google star 1Google star 2Google star 3Google star 4Google star 5
Our 2 mini-split units received their annual services today. Nixon arrived early for the service appointment. Before beginning his tune-up/cleaning, he asked if there were any issues that should be addressed during the visit. I mentioned an issue that occurred during the heating season. Both units(exterior washed/interior units checked for drainage and issues) were given a clean bill of health. Due to a leaking cooling line cap last year, there was a need for additional cooling material. Visit was punctual, friendly and professional. We even discussed setting up a twice a year maintenance schedule being proactive.
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Doug and Elizabeth Goudy profile picture
Doug and Elizabeth Goudy
Google star 1Google star 2Google star 3Google star 4Google star 5
Company owner Nixon was extremely knowledgeable and was able to explain things such that even I could understand it. He and his staffer Zeke were efficient and courteous. His price quote stayed the same from start to finish and work was done under the time estimate. I am 1000% pleased and will now use his company for routine maintenance.
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Robert Fischer profile picture
Robert Fischer
Google star 1Google star 2Google star 3Google star 4Google star 5
The big fear when hiring an hvac contractor is that the service technician is looking for every opportunity to upsell or replace a furnace or ac unit. At least, I feel this way. But, what I experienced with Firestone was straight forward and honest. Instead of upselling, Nixon quickly determined where to look for the problem and then he fixed it. Easy peasy. Firestone over delivered. I will call them again when I need my hvac serviced again.
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Kevin Devaney profile picture
Kevin Devaney
Google star 1Google star 2Google star 3Google star 4Google star 5
Only company I use.
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Kevin Devaney profile picture
Kevin Devaney
Google star 1Google star 2Google star 3Google star 4Google star 5
Great service, very reliable and "Nixon" is a pleasure to work with.
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Ryan Griss profile picture
Ryan Griss
Google star 1Google star 2Google star 3Google star 4Google star 5
We had a second HVAC unit installed in our large home. It was built with only a single unit which struggled to heat and cool the second floor. It was a big project, but service and installation went smooth.
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Lindsy Robinson profile picture
Lindsy Robinson
Google star 1Google star 2Google star 3Google star 4Google star 5
Nixon was amazing. He was so professional. Very personable. Gave us options and wasn’t trying to rip us off. He knew the issue and helped us solve it! Will recommend to others!
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Blake Drnec profile picture
Blake Drnec
Google star 1Google star 2Google star 3Google star 4Google star 5
We had great service, prompt estimate by the owner named Nixon, and a good price. Very friendly, no pushy sales, gave us three options and actually took less time than expected! Highly recommend this company owned by Nixon. Oh, and Nixon comes on site to ensure quality work at each appointment!
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Jeff Hanks profile picture
Jeff Hanks
Google star 1Google star 2Google star 3Google star 4Google star 5
I've had Nixon from Fireside Heating & Cooling over to our house twice in the last week (two separate issues) and he's been nothing but professional. He quickly identified the issue both times and either repaired or advised on the best course of action. Most importantly for me, he explained what was going on, how to prevent it in the feature and didn't try to scare us with "this is going to be a huge problem - you need to spend a large amount of money or replace your furnace and AC right now", like we so often here. He was very pragmatic in his approach and its clear he's trying to win customers the right way, through great customer service, transparency, and being fair.

Other Services

AC Repair

AC Repair

Keep your home cool and comfortable with our expert AC repair services. We quickly diagnose and fix issues to restore your system's performance.

AC Replacement Icon

AC Replacement/Installation

Upgrade to a more efficient air conditioning system with our professional installation services. We’ll help you find the perfect unit for your home.

Furnace Repair

AC Maintenance

Regular AC maintenance extends the life of your system and keeps it running efficiently. Schedule your tune-up today to prevent costly breakdowns.

Furnace Replacement

Furnace Repair

When your furnace breaks down, count on our skilled technicians to get it back up and running quickly, ensuring your home stays warm.

Furnace Maintenance

Furnace Maintenance

Prevent unexpected furnace issues with our thorough maintenance services, designed to keep your heating system in peak condition.

Ductless Heating & Cooling

Ductless Heating & Cooling Services

Experience flexible, energy-efficient comfort with our ductless heating and cooling solutions, perfect for any space.

Frequently Asked Questions

How do I know whether to repair or replace my furnace?
The age of the system matters most here. A furnace under 10 years old with a single issue is usually worth repairing. Once a system is 15 years or older, especially one that’s been needing repairs regularly, replacement becomes the more financially sound decision. A reliable heating system that’s properly installed will outperform a patched older unit every winter for the next 15 to 20 years. We’ll give you an honest assessment of where your system stands rather than defaulting to whichever option costs more.
AFUE measures how efficiently a furnace converts fuel to heat. A furnace with an 80 AFUE rating converts 80 percent of the natural gas it burns into usable heat. High-efficiency models reach 95 to 98 AFUE. For Highlands Ranch homes that run heating systems heavily through long winters, the energy savings from a high-efficiency unit typically justify the higher upfront cost within a few years. We can run those numbers for your specific home so the decision is based on real data.
Most standard residential furnace replacements are completed in a single day. Jobs that involve ductwork modifications, new gas line work, or venting changes may take longer. We’ll give you a clear timeline during the estimate so you can plan accordingly.
Yes. We provide free estimates on furnace replacement and installation. Furnace replacement cost varies based on the system you choose, the complexity of the installation, and any additional work required such as ductwork or venting updates. We’ll walk you through all of it transparently before any work begins.

We serve homeowners throughout the Denver metro area including Aurora, Castle Rock, Centennial, Denver, Greenwood Village, Parker, Lakewood, Littleton, Lone Tree and Highlands Ranch.

Let's Get Your Home Ready for Winter

A furnace replacement is not something you want to sort out under pressure. The homeowners who come to us in September or October have time to make a good decision. The ones who call in January during a cold snap are working with fewer options and tighter timelines.

We’d rather you be the first group.

Fireside Heating & Cooling is a locally owned, veteran owned HVAC company with more than 11 years serving the Highlands Ranch area. We’re fully licensed and insured, and we stand behind every installation with a 100 percent satisfaction guarantee.

Call us today or request a free estimate online. We’ll help you find the right furnace, install it correctly, and make sure your home is ready before the cold arrives.

How It Works

Simple Steps to Your Free Quote

Getting started with your HVAC project is easy. Follow these three simple steps, and we’ll provide you with a transparent, no-obligation quote that fits your needs and schedule.

Fireside Heating & Cooling
1

Get In Touch

Call us or submit an online request, and rest assured, a dedicated member of our team will be in touch with you promptly.

2

Discuss Your Project

Speak to our experts about your project, and we’ll discuss product choices transparently, explaining the process step by step so you can make informed decisions.

3

Get a Quote

We’ll provide an accurate, obligation-free quote and work with you to schedule your HVAC project at a time that suits you.

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