Open 24/7 for emergencies
Gas furnace replacement in Ashburn runs $4,285 to $14,040 installed when the AC stays. In Broadlands and Belmont, nine in ten owners heat with gas.
Price range
$4,285-$14,040
8yrs @ 7.99%
$61/mo
15yrs @ 9.99%
$46/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
Two of our heating technicians beside a gas furnace, the cooling coil on top of it and the water heater to the right.
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 gas furnace on its own, 2 to 5 tons, keeping the air conditioner you have. A single-stage furnace in a small house sits near the bottom; a modulating one in a big house, near the top.
A gas furnace alone, keeping your air conditioner, installed
$4,285 to $14,040
or $71/mo at 0% APR for 60 months
A furnace and air conditioner together, installed
$8,898 to $23,000
or $148/mo at 0% APR for 60 months
Repair 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, at no charge, before anything is ordered.
Natural gas or propane, in a house, a townhouse or a condo, we replace them all. Oil furnaces we don’t.
What’s different in Ashburn
Gas is the Ashburn default: more than four in five owner homes heat with it, and in Broadlands and Belmont about nine in ten. Those two went up around 2004 and 2005, so a builder’s furnace still running there is close to twenty, the far end of what most gas furnaces give. The outdoor unit beside it has had the rougher life, out through every July heat wave and January freeze, and it’s usually the half that quits first. So by the time the furnace is done, the air conditioner may already be a second one with years left.
Keeping that air conditioner means the new furnace has to suit it. The cooling coil usually sits right on top of the furnace cabinet, so the new cabinet has to meet the coil’s width, and its blower has to move the air that coil was matched for. Read the outdoor unit’s label first. Made in roughly the last ten years, it’s usually worth keeping. If it says R-22, it almost certainly predates 2010, and it’s next in line.
Ashburn Farm and Ashburn Village sit a generation earlier: the typical owner’s house there dates from 1998, and about half the homes went up from 1980 through 1999. Most builder furnaces there are long gone, and the furnace and air conditioner are often different ages by now. That’s the case for pricing only the one that’s done, with the $8,898 to $23,000 range for the pair beside it.
Close to four in ten Ashburn homes are townhouses, more than half in Loudoun Valley Estates, and there the furnace is often up in the attic or a top-floor closet. In the attic, a high-efficiency model’s condensate line needs protecting from a hard freeze, and the new furnace has to come up through the same hatch the old one goes down.
Neighborhood by neighborhood
Census figures for the owner-occupied homes in each place, and what that usually means for the furnace that’s there now.
| Place | Median home built | Most homes are | Heated with | The furnace there now |
|---|---|---|---|---|
| Ashburn | 1998 | single-family houses, about 4 in 10 | gas, about 8 in 10 | 1980s and 90s houses, many on their second furnace. |
| Brambleton | 2011 | townhouses, about 5 in 10 | gas, about 8 in 10 | Townhouse furnaces in closets and attics. |
| Broadlands | 2004 | single-family houses, about 6 in 10 | gas, about 9 in 10 | Builder gas furnaces, many now near twenty years old. |
| Loudoun Valley Estates | 2013 | townhouses, about 6 in 10 | gas, about 8 in 10 | Townhouse furnaces in closets and attics. |
| Belmont | 2005 | single-family houses, about 6 in 10 | gas, about 9 in 10 | Builder gas furnaces, many now near twenty years old. |
| Moorefield | 2015 | townhouses, about 6 in 10 | gas, about 7 in 10 | Townhouse furnaces in closets and attics. |
| One Loudoun | 2015 | townhouses, about 4 in 10 | gas, about 7 in 10 | Townhouse furnaces in closets and attics. |
| University Center | 1996 | condo and apartment buildings, about 4 in 10 | gas, about 8 in 10 | Condo and apartment buildings: compact furnaces in closets. |
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
When it’s time
The coil on an upflow furnace sweats all summer. When its drain pan cracks or the drain line backs up, water drips into the furnace and rusts the burners and the heat exchanger from the top down, which is how a furnace ends up done while the air conditioner still cools fine. Fix the drain with the furnace, or the new one rusts the same way.
A house from the 2000s often runs the furnace it was built with. Around twenty years, inducer motors and control boards start to go, one after another.
It’s the wall that keeps the burner’s exhaust out of the air the furnace blows through the house. Nobody patches one; a crack ends the repair conversation.
Permits, locally
Loudoun County requires a permit to swap a gas water heater or furnace. Since October 2025, a replacement that keeps the same BTUs in the same spot needs no plans. 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.
Ask how they picked the size. Copying the old nameplate repeats whatever was guessed when the house was built.
A new furnace has to work with the coil and the outdoor unit already there. Ask whether they looked at both before quoting a furnace on its own.
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 1,132 reviews. Read them on our reviews page.
Oscar and Ndung were great technicians for our HVAC install! Very knowledgeable and friendly. Would recommend them to others!
Questions
It can. Loudoun County’s October 2025 notice spares a gas replacement from plan review only when it doesn’t add BTUs or move the appliance. Going up a size because the basement got finished, or moving the furnace out of a townhouse attic, can mean plans go to the county first. A same-size furnace in the same spot skips that step.
Yes. Propane heats about one Goose Creek Village owner home in ten, more than anywhere else in Ashburn, and we replace propane furnaces like natural gas ones. The HVAC replacement cost estimator gives your range, and a tech checks the gas line and venting before the price goes in writing.
$4,285 to $14,040 installed for a gas furnace on its own, keeping the air conditioner you have; size and efficiency set where yours lands. A furnace and air conditioner together run $8,898 to $23,000. The HVAC replacement cost estimator gives your house its own number.
Fix the small parts on almost any furnace. Past fifteen years, with a repair over a third of the price of a new one, replacing usually wins. Not sure which you’re looking at? The diagnostic visit is $99, and the tech prices the repair before starting it.
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 furnace 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 Ashburn 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.