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Gainesville AC replacement, with the gas furnace kept, is $5,942 to $14,450 installed. First, check which outdoor unit it is.
Price range
$5,942-$14,450
8yrs @ 7.99%
$84/mo
15yrs @ 9.99%
$64/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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One of our HVAC technicians moving a new condenser up a driveway, the van behind him.
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
The same price book our estimator runs on, for a central air conditioner on its own, keeping the furnace you have. A single-stage unit on a small house sits near the bottom; a variable-speed one on a big house, near the top.
A central air conditioner alone, keeping your furnace, installed
$5,942 to $14,450
or $99/mo at 0% APR for 60 months
An air conditioner and furnace together, installed
$8,898 to $23,000
or $148/mo at 0% APR for 60 months
A heat pump in the AC’s place, installed
$8,499 to $21,650
or $142/mo at 0% APR for 60 months
Diagnostic visit, if it may be worth fixing
$99
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 cost estimator narrows it to your house. Then a tech measures, and you get the installed price in writing before anything is ordered.
With Comfort+ membership at $199 a year, the diagnostic visit is included, and half of each repair bill is banked toward replacing that system, up to $1,500.
What’s different in Gainesville
Gas heats about eight in ten owner homes in the Gainesville CDP, which puts a furnace inside and a central air conditioner outside, and a worn-out outdoor unit can go by itself. Plenty of 2000s houses here carry two of those setups, one for the main floor and basement, one for the bedrooms. Read the label on each outdoor unit first: builders often put a heat pump on the upstairs system, and from the yard the two look nearly alike.
The build year sets the refrigerant. In the CDP, 2,087 of the 4,951 owner homes went up from 2000 through 2009, and a builder condenser from those years most likely holds R-22; at about twenty, that’s the unit this page is usually about. Another 1,480 date from the 2010s and 428 from 2020 on, most likely on R-410A, which is still serviced. On those, a failure is usually a repair, and the youngest may still be inside the maker’s parts warranty.
Virginia Oaks dates to 1994, so its 561 houses are past the age of a first air conditioner, and its design guidelines make the replacement easy: a new exterior air conditioner where the old one stood needs no DRC application. A new spot is different, since adding or changing a structure on the lot needs an approved Exterior Changes Application first. Heritage Hunt, built after its 1997 zoning, sits outside the Census figures above.
About a third of Gainesville homes are townhouses, and in a 2000s row the condenser usually sits on a small pad out back or under the deck. Prince William County lists a condensing unit traded for the same type, where the old one stood, as needing no permit. If the furnace under your coil is the same 2000s vintage, have the pair priced at $8,898 to $23,000 too; a furnace replaced in recent years makes the AC alone the job.
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
When it’s time
In a two-system Gainesville house, the outdoor units are often different ages: one replaced after a failure, one still from the build. Replace the worn one and leave the younger one be. Each system gets its own quote, and the new coil sits on that system’s furnace.
A house from the 2000s often cools with the condenser it was built with. Past fifteen years, compressors and fan motors start to go, one after another.
It’s the pump at the heart of the outdoor unit and its costliest part. Out of warranty on an older unit, the repair can come close to half the price of a new AC, the point where Goodman says replacing may be the better money.
Permits, locally
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.
Our Virginia Class A contractor license, 2705192276, is on the side of the van.
Choosing who installs it
Questions to ask anybody who quotes you, us included.
On a 2000s Gainesville house still running its first furnace, an honest quote prices both: the AC by itself at $5,942 to $14,450 and an AC with a furnace at $8,898 to $23,000. Then you weigh one job now against another in a few years.
Ask how they picked the size. Copying the old nameplate repeats whatever was guessed when the house was built.
The outdoor unit and the coil on the furnace are rated as a pair. Ask whether the quote replaces both, and what happens to the line set.
A good company puts the repair price next to the replacement range and lets you choose. Already holding somebody’s big number? Take the free second opinion first.
Two of our crew going over a work order before the day's calls.
From our Google reviews
5.0 stars across 1,131 reviews. Read them on our reviews page.
They replaced my AC system and got it up and running with great service. Moises and Efrain are great!
Where we work
Next door to Gainesville: Catharpin, Haymarket, Broad Run, Bristow and The Plains.
Questions
Start with the condominium association. Heritage Hunt counts four condominiums among its 1,863 homes, and Prince William County treats condominium buildings as commercial, so its residential no-permit line for a like-for-like swap doesn’t reach them. The association’s rules decide where equipment sits on the building and who signs off.
Maybe once, if the leak is found and fixed. Every pound going back into an R-22 system is reclaimed, and on a condenser that old the money often goes further toward the new one. The $99 diagnostic visit finds the leak and prices the repair, and you choose with both numbers.
$5,942 to $14,450 installed for a central air conditioner on its own, keeping the furnace you have; size and efficiency set where yours lands. An AC and furnace together run $8,898 to $23,000. The HVAC replacement cost estimator gives your house its own number.
It’s worth pricing. A heat pump cools exactly like an AC and also heats on mild days, so with your gas furnace it becomes dual fuel. A heat pump system runs $8,499 to $21,650 installed, and we’ll price it both ways.
Ready when you are
Call, or send the form at the top. A tech measures the house and puts the installed price in writing before anything is ordered, and if the old AC is worth fixing, 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 1,131 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.