Furnace replacement in Middleburg.
A new propane or gas furnace in Middleburg runs $4,285 to $14,040 installed, keeping your AC or heat pump. In 20117, propane outnumbers piped gas four to one.
- Installed price in writing
- Sized to the house, not the old nameplate
- Dedicated HVAC team
Get your furnace priced in writing
Middleburg furnaces mostly burn propane, and they light from late October into April.
Piped gas barely reaches 20117. Of the ZIP’s 927 owner homes, the Census counts 41 heating with utility gas and 187 with propane from a tank on the lot, while 582 heat with electricity. So a Middleburg furnace coming due is most often a propane furnace, and the air conditioner or heat pump out back usually stays put.
It works a long season. The NOAA co-op in Purcellville, 12 miles north at about Middleburg’s height, puts the median first freeze on October 25 and the last on April 16, with January nights averaging 24.5 degrees. A weather station in Middleburg read 4 below on the morning of January 23, 2025, a reading the Weather Service counts as unofficial. The new furnace gets sized to what the house loses on a morning like that, measured, not read off the old label.
Then there’s the chimney. About one home in four across 20117 went up before 1940, and the Town’s design guidelines note that some flues in the Historic District still carry furnace exhaust. A high-efficiency propane furnace vents through its own plastic pipe instead, which can leave a water heater alone in a flue built for more. The guidelines want the chimney kept regardless, and a vent a public street can see needs the Historic District Review Committee’s approval before it goes in.
A propane furnace still depends on the power lines. Its igniter, inducer fan, blower and control board all run on electricity, and the February 2010 snowstorm put out power throughout Loudoun County. About a tenth of 20117’s land lies in Fauquier County, where the County’s building office in Warrenton wants a permit for any fuel-fired appliance, a same-spot propane furnace included.
Middleburg houses, by the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
Middleburg
ZIP 20117 as a whole: every Middleburg address, the Town and the farms around it, about a tenth of the land in Fauquier County. The Census place for the Town alone has too few homes for steady figures.
- Median home built1986 Census
- Built before 1980about 5 in 10 Census
- Built since 2000about 3 in 10 Census
- Most homes aresingle-family houses, about 8 in 10 Census
- Heated withelectricity, about 6 in 10 Census
- Rentedabout 3 in 10 Census
- Propane heats a real share of homes here, and we replace propane furnaces too.
- Most homes here heat with electricity, usually a heat pump; a furnace swap here is for the gas and propane houses.
What a new furnace costs in Middleburg.
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 Middleburg.
The old flue needs a liner to keep the furnace venting
A masonry chimney that’s cracked, or too big for the furnace drafting up it, can need a liner before it’s safe to keep using. On a furnace already fifteen or older, price a sealed high-efficiency furnace that vents through the wall beside the liner job. In the Historic District, the chimney itself stays either way.
You heat with propane
We replace propane furnaces as well as natural gas ones. The new furnace is set up for propane before it’s lit, and the quote is written for your house.
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.
Who signs off on a new furnace in Middleburg.
Loudoun County
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.
How to pick the best furnace replacement company in Middleburg.
Questions to ask anybody who quotes you, us included.
Did they ask what runs the house in an outage?
If a generator backs up the house, the new furnace’s blower and board will run on it through the next long outage. Ask whether the quote accounts for the generator’s size and how the furnace circuit is fed.
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.
David and the install team that came over were friendly, knowledgeable and professional. Happy with the install of my Trane system. Tyler was a pleasure to work work with in getting me the best price. He’s got a good thing going over there. I’m glad I went with them!
5.0 stars across 884 Google reviews. Read them on our reviews page.
Furnace replacement questions from Middleburg.
Who issues the permit for a new propane furnace in Middleburg?
Loudoun County, inside the town limits and out; its gas swap rule is in the permit box on this page. Inside the limits, the Town’s guidelines add that its Zoning Administrator may need to clear the job before the County issues the permit. On the Fauquier side of 20117, it’s Fauquier County’s building office.
Is a two-stage furnace worth it in a Middleburg house?
Often, in a big or drafty one. A two-stage furnace runs its low fire through most of a winter like Purcellville’s and goes to high fire only on the hard mornings, so the far rooms swing less between cycles.
How much does a new furnace cost in Middleburg?
$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 Middleburg.
More from SwiftPro in Middleburg
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 Middleburg 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.