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Furnace and AC replacement in Gainesville runs $8,898 to $23,000 installed. Half of 20155’s owner homes date from 2005 or before, so plenty of pairs are due.
Price range
$8,898-$23,000
8yrs @ 7.99%
$126/mo
15yrs @ 9.99%
$96/mo
Monthly figures on the starting price, the whole price financed, on approved credit. The lender sets the final terms. How financing works
Get your price in writing
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5.0 stars across 1,132 reviews
One of our technicians with a new Trane outdoor unit he just installed beside a Northern Virginia house.
Licensed and insuredVirginia Class A contractor #2705192276
24/7 emergency serviceOften same-day, and we will tell you honestly when we can get there.
Our own HVAC installersA dedicated heating and cooling team, separate from our plumbers
Price in writing firstYou see every option priced before anything is ordered
What it costs
$8,898 to $23,000 installed for a furnace and air conditioner replaced together, 2 to 5 ton, from the same price book as our estimator. Where you land depends on the size of the house, the efficiency you pick, and what the ductwork and venting need.
Furnace and AC together, installed
$8,898 to $23,000
or $148/mo at 0% APR for 60 months
Furnace alone, keeping your AC
$4,285 to $14,040
or $71/mo at 0% APR for 60 months
Heat pump system instead
$8,499 to $21,650
or $142/mo at 0% APR for 60 months
Monthly figures: 60mo @ 0% APR on each starting price, the whole price financed, on approved credit. Longer plans lower the payment and cost more in total. The lender sets the final terms. How financing works
The HVAC replacement estimator gives your house its own number. Then we measure, and the price is in writing before anything is ordered.
Two years of labor come with every install. Monthly plans are on our financing page.
What’s different in Gainesville
Put every owner home in the 20155 ZIP in order by the year it was finished, and the one in the middle dates from 2005, by the Census Bureau’s count; inside the part the Census calls Gainesville, it’s 2007. So the middle Gainesville house is about twenty, and so is a furnace and air conditioner that went in with its drywall, if nobody has changed them since. Same birthday, and the new outdoor unit’s coil sits right on top of the old furnace: that’s the case for doing both at once.
About four in ten owner homes inside the Census line went up in 2010 or later. If yours is one, this page probably isn’t for you yet: a system that young most likely runs R-410A, still made and serviced, and a failure on it is usually a repair, not a pair. The $99 diagnostic visit puts that repair price beside the replacement range, so you see both numbers before deciding.
Virginia Oaks, from 1994, has likely been through this once already: most of its houses are past the age of a first pair, and some second pairs there went in before 2010 themselves. Replacing an exterior air conditioner needs no application under its design guidelines. Heritage Hunt was built after its 1997 zoning and is left out of the Census figures, and its systems run from originals to replacements.
Not sure which you have? Read two labels. The furnace’s rating plate is inside its front panel, and the outdoor unit’s plate names its refrigerant and often its year. Two dates from before 2010 and R-22 outside is the textbook case for replacing both; one old date and one young one means you may only need half.
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
When it’s time
A buyer’s home inspector notes the age of the furnace and the outdoor unit, and on a 2000s pair that line can come back as a request for a credit. Pricing the pair first tells you whether to replace before listing or negotiate with a real number.
Plenty of houses built since 2000 still run the builder’s furnace and AC. They wear out on about the same schedule, so when one goes, price the pair.
A new outdoor unit needs a matching coil, and on a gas system the coil sits on the furnace. If the furnace is as old, do both and open that closet once.
Permits and sign-offs
Prince William County lists any work that alters a home’s heating and air conditioning as permit work, but swapping an electric furnace, heat pump or air conditioning condensing unit for the same type of unit in the same spot is an ordinary repair that needs no permit. Source.
Prince William County requires a permit to replace a gas or propane furnace or a gas appliance such as a water heater, even like for like. Replacing an electric water heater with one the same size in the same spot needs no permit. Source.
Our Virginia Class A contractor license, 2705192276, is on the side of the van.
Choosing who installs it
Ask every company that quotes the job, us included.
A quote for the pair should name the age and refrigerant of what’s there now. If the air conditioner turns out to be a 2016 replacement, you may only need the furnace, at $4,285 to $14,040 installed.
The old size is a guess somebody made years ago. Ask whether they measure the house and check the ductwork first. Too big short cycles; too small runs all afternoon in August.
Furnace, outdoor unit, matching coil, refrigerant lines, thermostat, permit and hauling the old one away. If it isn’t on the paper, ask.
Our free second opinion looks at the system you were quoted on and tells you what it actually needs, with our price if you want it.
Two of our crew going over a work order before the day's calls.
The system we put in first
Built to take a beating. Put in by our crew.
Heat lamps, snow and rain on one outdoor unit: that’s Trane’s own film. We’re a Trane Comfort Specialist, on Trane’s own dealer locator, and when you pick a Trane, our crew puts it in.
Films: Trane’s own.
From our Google reviews
5.0 stars across 1,132 reviews. Read them on our reviews page.
Ndung and Oscar were great. Everything went smoothly, and after the install they made sure to show me everything I needed to know about the new unit.
Where we work
Next door to Gainesville: Catharpin, Haymarket, Broad Run, Bristow and The Plains.
Questions
Not on age alone. A 2015 system runs R-410A and is about eleven years old, so most of what goes wrong with it is worth fixing. Get the repair priced first, and keep the $8,898 to $23,000 range in mind for later.
Not when it replaces the old one where it stood: its guidelines put replacing an exterior air conditioner on the list of changes that need no application. Moving it somewhere new is different, because anything that adds or changes a structure on the lot needs an approved Exterior Changes Application first.
$8,898 to $23,000 installed for the pair, by size and efficiency. A furnace alone, keeping your AC, is $4,285 to $14,040. The HVAC replacement estimator gives your house its own number.
No. If the AC is young and only the furnace failed, replace the furnace. If they’re the same age, do both: a new outdoor unit needs a matched coil, and one built for the old refrigerant isn’t rated for the new one.
Ready when you are
Call, send the form at the top, or take the HVAC replacement estimator first. We measure before we quote, and if a repair makes more sense than a new system, you’ll hear that first.
SwiftPro Heating, Cooling & Plumbing
4230 Lafayette Center Dr N, Chantilly, VA 20151
44679 Endicott Dr, Suite 211, Ashburn, VA 20147
Virginia Class A contractor license #2705192276
SwiftPro Heating, Cooling & Plumbing is a licensed, BBB Accredited (A rating), independently owned heating, cooling and plumbing company in Chantilly, serving Gainesville and the rest of Northern Virginia. Virginia contractor license #2705192276. 5.0 stars across 1,132 reviews on Google, Angi, Yelp, the BBB and Facebook. SwiftPro maintains a dedicated HVAC team and a dedicated plumbing team.
From SwiftPro Heating, Cooling & Plumbing in Chantilly. Housing figures are the Census Bureau’s American Community Survey, 2020 to 2024, for each place named; permit, water and sewer facts link to each office’s own page and were checked in September and October 2026.