Same-Day Service
Most service calls handled same-day across the Denver metro — and we answer the phone 24/7.
Furnace Replacement & Installation
The Right Furnace for Your Home — Installed by Denver's Own
Replacing a furnace is one of the bigger decisions a homeowner makes, and getting the sizing and efficiency right matters as much as the equipment brand. Done has been installing furnaces across the Denver metro since 1999, and our licensed technicians take the time to assess your home’s square footage, insulation, ductwork condition, and fuel type before recommending a system — not just swapping out whatever was there before. That means you get a furnace that actually performs the way it should.
We carry high-efficiency gas furnaces from trusted manufacturers and offer flexible options to fit a range of budgets. Whether you’re replacing an aging unit before it fails or upgrading to a modern high-AFUE system to lower your energy bills, Done makes the process straightforward. Ask us about our financing options to spread the cost over time with no surprises.
- Proper Load Calculation We size every furnace to your home using Manual J load calculations — never a guess — so you're not paying to heat more air than your house needs.
- Fully Licensed & Insured Every installation is performed by a licensed HVAC technician, ensuring your equipment is installed to code and backed by Done's workmanship guarantee.
- Same-Day & Next-Day Availability When Denver temperatures drop, waiting weeks for a new furnace isn't an option. Done works hard to get you scheduled fast — often same day or next day.
Signs You Need a New Furnace
Is It Time to Replace Your Furnace?
Not every furnace problem calls for a replacement, but some signs point clearly toward the end of a system's useful life. Here's what Denver homeowners commonly see before they call us for a new installation.
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Furnace Is 15–20+ Years Old
Most gas furnaces have a service life of 15 to 20 years. If yours is in that range and starting to have problems, repairs often cost more than they're worth compared to a new high-efficiency unit.
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Heating Bills Keep Climbing
An aging furnace loses efficiency over time. If your gas bills are noticeably higher than they were a few winters ago and nothing else has changed, your furnace is likely working harder than it should.
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Frequent or Expensive Repairs
One or two repairs over a furnace's lifetime is normal. But if you're calling for service every season — or facing a single repair that costs more than half the price of a new unit — replacement usually makes more financial sense.
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Uneven Heat or Comfort Problems
If some rooms are cold while others are too warm, and your ductwork checks out, a declining furnace that can no longer maintain steady output is often the culprit.
What We Install
Furnace Installation Services Done Provides
Done installs a full range of gas furnace systems for Denver-area homes, from standard single-stage units to variable-speed, high-efficiency systems designed for maximum comfort and lower operating costs.
- High-Efficiency Gas Furnaces We install 96%+ AFUE condensing furnaces that extract maximum heat from every cubic foot of natural gas — a meaningful upgrade for most Denver homes still running older 80% equipment.
- Variable-Speed & Two-Stage Systems Variable-speed blowers and two-stage burners deliver more consistent temperatures, quieter operation, and better humidity control than single-stage units — especially noticeable during Denver's shoulder-season days.
- Ductwork Assessment & Modifications A new furnace is only as good as the duct system feeding it. We inspect existing ductwork for leaks, obstructions, and sizing mismatches, and we handle any modifications needed at the time of installation.
- Thermostat Upgrades & Commissioning Every installation includes full system commissioning — we set up and test your thermostat, verify airflow at every register, confirm ignition and heat exchanger integrity, and walk you through operating your new system.
Our Installation Process
How Done Handles Your Furnace Installation
We keep the process clear and low-stress from the first call to the final walkthrough. Here's what to expect when you choose Done for your furnace installation.
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Call or Schedule Online
Reach us at 833-539-9153 or book online. We'll ask a few questions about your current system, your home size, and your timing so we can come prepared.
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In-Home Assessment & Quote
A licensed Done technician visits your home, assesses your heating load, inspects the existing ductwork and gas line, and gives you a clear, written quote — no estimates that balloon later.
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Professional Installation
We remove and dispose of your old equipment, install the new furnace to manufacturer specs and local code, and seal and test all connections. Most residential installations are completed the same day.
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Commissioning & Walkthrough
Before we leave, we run a full system commissioning check, verify safe operation of the heat exchanger, and walk you through the controls, filter location, and what to expect from your new system.
Current Specials
Save on the work your home needs most.
Why Choose Done
Upfront Pricing
Flat-rate pricing approved before work begins — no surprises on the invoice.
Licensed & Insured
Fully licensed, bonded, and insured — plumbing, HVAC, and electrical under one roof.
Satisfaction Guaranteed
If it isn't right, we make it right — backed by our workmanship guarantee.
Ready for a Warmer, More Efficient Winter?
Done has been Denver's trusted furnace installation team since 1999. Call today or schedule online — we'll take it from here.
What Our Customers Say
Don't just take our word for it — hear from our satisfied customers
★★★★★
Within less than a week, we were able to benefit from the knowledge, courtesy, respect and patience of 2 excellent technicians from Done, Jay and Jack. They both helped us with our heating and air conditioning. I'm sure we will be using them and the resources they have available to them in the future. Very highly recommended!!!
★★★★★
My 25+ year old furnace was dying. DONE repaired it in 2014 and again last year. I decided to go with new heat pump system. Their repair/sales/installation/electrician staff were incredibly professional and effecient. I would highly recommend this company for your Heating/Cooling/Electric needs! They also submitted all information required for the Xcel Energy rebate. Great work guys! Thank you!
Maintenance Membership
Join the Care Club
Total home service care, on a schedule.
Members get priority scheduling, seasonal HVAC tune-ups, an annual plumbing & electrical safety inspection, and exclusive discounts — for less than the cost of a single emergency call.
- Priority scheduling
- Seasonal HVAC tune-ups
- Annual safety inspection
- Exclusive member discounts
- Free dispatch on repairs
- No long-term contracts
Frequently Asked Questions
How long does a furnace installation take?
Most standard residential furnace replacements take between four and eight hours, depending on the complexity of the install, whether ductwork modifications are needed, and the accessibility of your mechanical room. Done’s technicians arrive with the equipment staged and ready so we’re not making extra trips, and most jobs wrap up the same day we start.
What size furnace does my home need?
Furnace sizing is not one-size-fits-all, and an oversized or undersized unit causes real problems — short cycling, humidity issues, uneven heat, and shortened equipment life. Done performs a proper Manual J load calculation that accounts for your home’s square footage, ceiling height, insulation levels, window area, and local climate data. We never just match the tonnage of what was there before.
Do you offer financing for furnace installation?
Yes. Done offers flexible financing options to help Denver homeowners manage the cost of a new furnace without having to wait. Visit our financing page for current options, or ask your technician during your in-home assessment. We want getting a safe, reliable heating system to be as straightforward as possible.
What brands of furnaces do you install?
Done works with a select group of proven, manufacturer-backed furnace brands that we’re confident standing behind. During your in-home assessment, your technician will walk you through the available options for your home and budget, explain the efficiency and feature differences, and give you a recommendation — with no pressure to go beyond what you need.
*Offers cannot be combined with other promotions or applied to dispatch fees. No cash value. Must present offer at time of service. Call for details.
