Open 24/7 for emergencies
Furnace replacement in Paeonian Springs: $4,285 to $14,040 installed, propane or gas, AC untouched. Propane heats nearly half the owner homes.
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
Send this and the office calls or texts you back to set a time.
We’ll call or text this number about your request. By sending it you agree to our terms and privacy policy.
Rather talk now? (703) 997-9757
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 Paeonian Springs
Propane heats nearly half the owner homes in ZIP 20129, electricity about 35 percent and oil nearly one in five, while natural gas registers at zero. So a furnace replacement here is mostly a propane furnace. If your house burns oil, we don’t work on oil burners; a propane furnace or a heat pump is what we would price instead. Either way the answer starts as a range, $4,285 to $14,040, and the estimator quiz narrows it to your house.
The median owner home here dates to 1997, so the furnace is likely close to three decades old, and about one in four owner homes predate 1980. Furnaces from that era mostly exhaust through a flue or chimney. New high-efficiency furnaces send their exhaust out through plastic pipe, so the old chimney may end up unused. Loudoun County Fire and Rescue says to have heating equipment and chimneys cleaned and inspected every year by a qualified professional, so ask what happens to yours.
Loudoun County wants a permit on a gas furnace swap. Plans only come into it when the unit’s BTUs or its location change; a like-for-like replacement has been exempt from them since October 2025. A furnace picked too large, or moved, steps outside that. Ask the installer to put the new unit’s BTU rating beside the old one on the estimate and to say who files the permit.
Where the vent pipes leave the house matters in snow. A trained spotter measured 13.0 inches a mile southeast of town on February 21, 2015, and Loudoun’s building code uses a ground snow load of 30 psf. A side-wall intake and exhaust has to sit above where snow piles up, and the Purcellville station counts more than a hundred freezing nights a year to test whatever you choose.
When it’s time
A furnace near three decades old that needs a board one year and a blower the next is telling you something. Set each repair price beside the cost of replacing it, and the answer gets clearer. The $99 diagnostic gives you the repair side of that comparison, and $4,285 to $14,040 is the replacement side.
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.
In a 1997-era house the old flue or chimney may no longer suit a new furnace. The quote should name where the new vent leaves the house and what is done with the old one. Get it in writing, with the BTU rating of both furnaces, so the permit question has an answer before the work starts.
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.
We used Swifpro for a new hvac install and a plumbing repair. We felt the pricing for the hvac install was fair and offered a better product than their competitors. The techs were professional and timely.
Where we work
Next door to Paeonian Springs: Waterford, Hamilton, Leesburg, Lovettsville and Purcellville.
Questions
No, we don’t work on oil burners, and nearly one owner home in five in 20129 heats with oil. A gas or propane furnace alone, keeping your air conditioner, runs $4,285 to $14,040 installed, and a heat pump is the other direction to price. Take the estimator quiz for the figure that fits your house.
Not automatically. A furnace alone keeps the air conditioner you have. If the AC is original too, furnace and AC together run $8,898 to $23,000, and the diagnostic visit at $99 tells you whether either one earns a repair first.
$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 Paeonian Springs 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.