Open 24/7 for emergencies
A new gas furnace in a Catharpin house, AC kept, runs $4,285 to $14,040 installed, and propane furnaces are replaced here too.
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 Catharpin
By the Census, natural gas heats about one owner home in fourteen in ZIP 20143. Propane heats one in three, and electricity nearly half. So a furnace replacement in Catharpin is usually a propane job. A propane house needs its new furnace fitted with a conversion before the burners ever light, and the quote lists that as its own line. Tell us where the propane tank sits when you book.
About one owner home in twelve here burns oil, and we don’t replace oil burners. A house leaving oil can come to us for a propane furnace or a heat pump. Moving to propane means a tank and a supply line from your fuel dealer, so settle that before the furnace date, and let the quote show what the furnace itself costs.
The median owner home dates to 1986, and about four in ten were built before 1980, so a furnace in one of those houses is probably a replacement already. A bit under four in ten homes were finished from 2000 on, and their first furnaces are heading into their second decade. A heating system of that age is where a repair bill starts competing with a replacement quote.
Dulles averages 4604 heating degree days and 101.7 nights a year at or below freezing. Up to 30.0 inches fell near Bull Run in the January 2016 blizzard. A high-efficiency furnace breathes through plastic pipes in a side wall, so ask where the exhaust and intake will end and how snow drifts there. The pipes need clear air to run.
When it’s time
On a propane furnace from the 1986 median or earlier, repairs stack: igniter, circuit board, blower. When a second repair lands in the same season, set the repair total beside the installed price, $4,285 to $14,040, and decide with both numbers in hand. The diagnostic visit is $99.
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
Prince William County requires a permit to replace a gas or propane furnace or a gas appliance such as a water heater, even like for like. Replacing an electric water heater with one the same size in the same spot needs no permit. 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.
Your fuel decides the furnace and the paperwork, and the label on the outdoor unit decides whether it stays. A condenser from the 2010s beside a furnace from the build year suggests the heating side is the one to replace. A quote that skips both questions is a guess.
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.
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!
The system we put in first
Built to take a beating. Put in by our crew.
Heat lamps, snow and rain on one outdoor unit: that’s Trane’s own film. We’re a Trane Comfort Specialist, on Trane’s own dealer locator, and when you pick a Trane, our crew puts it in.
Films: Trane’s own.
Where we work
Next door to Catharpin: Gainesville, Haymarket, Centreville, Chantilly and Bristow.
Questions
Yes. Prince William County requires a permit to replace a gas or propane furnace, even like for like, so propane counts. An electric furnace traded for the same electric type in the same spot is an ordinary repair that needs no permit. Ask your installer which line your quote covers.
Often, if the condenser outside is sound and its coil suits the new furnace. The tech reads the label before writing anything. If both halves date from the same year and are tired, a furnace and air conditioner together runs $8,898 to $23,000 installed, and that is worth pricing beside the furnace alone.
$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 Catharpin 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.