Furnace replacement in Oakton.
Replacing just the furnace in Oakton, gas or propane, runs $4,285 to $14,040 installed while your AC stays put. The estimator quiz gets you your own number.
- Installed price in writing
- Sized to the house, not the old nameplate
- Dedicated HVAC team
Get your furnace priced in writing
In Oakton’s gas half, the furnace often outlasted the air conditioner beside it.
About half of Oakton’s owner homes heat with gas, and about four in a hundred run on propane, delivered to a tank outside. The gas is almost always Washington Gas: Fairfax County names it as the supplier for most of the county, and the exceptions it lists, served by Columbia Gas, are pieces of Chantilly and Herndon. Nearly all the other Oakton homes heat with electricity, usually a heat pump, which is a different job.
Half of the owner homes in 22124 were built before 1984 and half after, and nearly half of all homes here date from 1980 through 1999. A furnace in a 1980s house is rarely the first one, and furnaces and air conditioners almost never quit in the same year. The outdoor unit is usually the half that dies in the hottest week of July and gets replaced in a hurry, while the furnace keeps lighting for a few more winters. So it’s common for the cooling half to be ten or more years newer than the furnace under its coil.
Keeping that newer half takes three checks before the price is written. The outdoor unit’s label names its refrigerant: on R-22 it’s near the end of its own run, and keeping it only buys time. The coil perched on the old furnace has to match the new cabinet’s width, or a sheet metal transition joins the two. And the new blower is set for the air conditioner’s size, so the house cools the way it did last summer.
In the townhouse clusters off Jermantown Road and Miller Road, like Oak Marr Courts and Oakborough Square, the furnace tends to stand in a closet or a utility room on the lowest level, so whatever replaces it must pass through that same door. An inside unit of a row has only two outside walls for a high-efficiency furnace’s plastic vent pipes. On the big lots north of Jermantown Road, a large house often has a second furnace up in the attic serving the bedrooms, and only the one that’s failing has to go.
The furnaces across Oakton, place by place.
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 |
|---|---|---|---|---|
| Oakton | 1981 | single-family houses, about 4 in 10 | gas, about 6 in 10 | 1980s and 90s houses, many on their second furnace. |
| Difficult Run | 1982 | single-family houses, nearly all | gas, about 6 in 10 | 1980s and 90s houses, many on their second furnace. |
Oakton houses, by the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
Oakton
ZIP 22124 as a whole: every Oakton address. The Oakton Census place in the table also takes in streets with Vienna and Fairfax mail.
What a new furnace costs in Oakton.
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
- A furnace and air conditioner together, installed$8,898 to $23,000
- Repair diagnostic visit, if it may be worth fixing$99
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.
When a new furnace makes sense in Oakton.
The outdoor unit is newer by ten years or more
If the condenser’s label says around 2015 and the furnace’s says the 1990s, a failing inducer motor or control board is a reason to replace the furnace alone and leave the newer cooling half working.
The heat exchanger is cracked
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.
It’s fifteen or older and acting it
Fifteen to twenty years is a gas furnace’s usual run. Past that, parts get harder to find and each repair buys less time.
Who signs off on a new furnace in Oakton.
Fairfax County
Fairfax County requires a permit to replace any gas appliance, even like for like: a gas water heater, furnace or boiler. Replacing a fuel-burning appliance also needs a chimney vent certification. Source.
How to pick the best furnace replacement company in Oakton.
Questions to ask anybody who quotes you, us included.
Did they price more than one efficiency?
Ask for an 80 percent furnace and a 95 percent one side by side. The higher one exhausts sideways through PVC and drips condensate, so it needs a drain; the lower one usually keeps the chimney. Washington Gas’s rebates in Virginia begin with furnaces rated 95.1 percent, so the quote should say which side of that line yours sits on.
Did they size it to your house?
Ask how they picked the size. Copying the old nameplate repeats whatever was guessed when the house was built.
Did they check the air conditioner you’re keeping?
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.
Will they tell you if it’s worth fixing?
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.
What our customers say.
Moises showed up on time and was very thorough and quick. He diagnosed our problem and Tyler came in and gave us a great quote on a new unit. They came back and installed it the next day! They came through for us and I am very happy with their service. Will definitely use them again!
5.0 stars across 884 Google reviews. Read them on our reviews page.
Furnace replacement questions from Oakton.
I heat with propane in Oakton. Is a new furnace a different job?
Barely. It’s the same furnace a natural gas house gets, fitted with a propane kit before its first fire, and the price falls in the same $4,285 to $14,040 range. Mention propane when you book so the kit comes with it.
How much does a new furnace cost in Oakton?
$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.
Should I repair it or replace it?
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.
More from SwiftPro in Oakton.
More from SwiftPro in Oakton
The range first, then your number.
Call, or book online and pick a window. 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 is a licensed, BBB Accredited (A rating), independently owned heating, cooling and plumbing company in Chantilly, serving Oakton and the rest of Northern Virginia. Virginia contractor license #2705192276. 5.0 stars across 884 Google reviews. SwiftPro maintains a dedicated HVAC team and a dedicated plumbing team.
SwiftPro Heating, Cooling & Plumbing, 4230 Lafayette Center Dr, Suite N, Chantilly, VA 20151, (703) 997-9757. Book online, read our reviews, or see every town we serve.