Open 24/7 for emergencies
Gas furnace replacement in Sterling runs $4,285 to $14,040 installed when the AC stays. In Oak Grove, plenty of builder furnaces are around twenty.
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 Sterling
Close to six in ten Sterling owner homes heat with gas, but not evenly. Oak Grove is about nine in ten, Cascades about eight, Lowes Island about seven. Sugarland Run and the streets around Sterling Park split roughly down the middle with electric heat, and Countryside is only about two in ten on gas, where heat pumps do most of it.
The typical owner home in Cascades and Lowes Island went up in 1996, so the builder’s furnace there is usually gone, and the one heating the house now is often still in its first fifteen years. Oak Grove is the exception: its typical owner home dates from 2005, about eight in ten are townhouses, and many still run the furnace the builder set, around twenty now, when the small parts start failing one by one. Where the AC out back already got replaced, this is your page.
In Sterling Park and Sugarland Run, where about four in ten homes predate 1980, a gas house is usually on its third furnace or later, often in a basement utility room. A high-efficiency furnace there needs two paths a chimney-vented one never did: a plastic vent out through a rim joist or wall, and a drain for the water it makes, which in a finished basement may mean a small condensate pump. Both belong in the written quote.
A Sterling furnace also logs more hours than its age suggests. NOAA’s 1991 to 2020 normals count about a fifth more heating degree days at Dulles Airport, next door, than at Reagan National, so the same furnace burns noticeably longer each winter here than in Arlington.
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 |
|---|---|---|---|---|
| Sterling | 1979 | single-family houses, about 5 in 10 | electricity, about 5 in 10 | Mostly electric heat; gas furnaces are the minority. |
| Lowes Island | 1996 | single-family houses, about 6 in 10 | gas, about 7 in 10 | Townhouse furnaces in closets and attics. |
| Cascades | 1996 | townhouses, about 4 in 10 | gas, about 8 in 10 | 1980s and 90s houses, many on their second furnace. |
| Sugarland Run | 1983 | single-family houses, about 6 in 10 | gas, about 5 in 10 | 1980s and 90s houses, many on their second furnace. |
| Dulles Town Center | 1998 | condo and apartment buildings, about 5 in 10 | gas, about 9 in 10 | Condo and apartment buildings: compact furnaces in closets. |
| Arcola | 2017 | townhouses, about 5 in 10 | gas, about 8 in 10 | Townhouse furnaces in closets and attics. |
| Oak Grove | 2005 | townhouses, about 8 in 10 | gas, about 9 in 10 | Townhouse furnaces in closets and attics. |
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
When it’s time
Check both date plates. In Cascades, Lowes Island and Oak Grove the air conditioner is often the half already replaced after a hard summer. If yours went in within roughly ten years and still cools well, keep it and price the furnace alone, matched to the coil sitting above it.
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.
Fifteen to twenty years is a gas furnace’s usual run. Past that, parts get harder to find and each repair buys less time.
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 to see both BTU figures on paper. Loudoun County spares a gas furnace swap from plan review only when the input and the location stay put, so a bigger furnace, or one moved to another closet, sends plans to the county first. Know that before anything is ordered.
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.
Rich did a great job. We hit it off very well. He was on time, and we promptly gathered the necessary measurements. He explained all the details. He prepared the estimate while at the house. This work is for a HVAC full replacement.
Where we work
Next door to Sterling: Ashburn, Herndon, Reston, Great Falls and Chantilly.
Questions
Yes. Propane heats only about one Sterling owner home in a hundred, but around Dulles Town Center it’s closer to one in fifteen. A propane furnace is measured and priced in writing the same way, with the manufacturer’s propane conversion fitted and the burner checked on propane before we leave.
The owner does. About seven in ten homes there are rented, so a tenant often makes the call while the owner or a property manager decides. Tell us who approves it and the written price goes to them. A new vent through an outside wall usually needs the condo association’s say too.
$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 Sterling 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.