Open 24/7 for emergencies
A new furnace in Marshall runs $4,285 to $14,040 installed, keeping the cooling you have. Out here the new one usually burns propane, not natural gas.
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 Marshall
Natural gas barely figures in 20115: the Census counts 8 owner homes heating with it, against 424 on propane. So a Marshall furnace replacement usually means propane for propane, fed from a tank on the property. A new furnace arrives built for natural gas, and a conversion kit swaps its burner orifices and the spring in its gas valve before the first fire.
The price assumes your cooling stays, and in a Marshall propane house that’s often a heat pump, which carries the mild months, racks up the hours and is often the half already replaced. The new furnace has to suit the coil sitting on top of it and that coil’s rated airflow, so the quote should name the outdoor unit’s model too.
Most of these furnaces live in houses from 1970 to 1999: the Census counts 532 homes here from the 1970s, 605 from the 1980s and 511 from the 1990s. On the newer streets north of Main and the cul-de-sacs west of Rectortown Road, a furnace original to the house would be pushing thirty or well past it. Read the date on yours; late 1990s or early 2000s means price it this fall.
Marshall has no town government, so a new furnace answers to Fauquier County alone. The County treats any fuel-fired appliance as permit work, even in the old one’s exact spot, and its Department of Community Development on Courthouse Square in Warrenton issues trade permits over the counter the day the application arrives. Test the carbon monoxide alarm on that floor on install day; Fauquier Fire Rescue takes alarm requests through its public education page.
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
ZIP 20115 as a whole: every Marshall address, the village included. The Census place for the village alone has too few homes for steady figures.
When it’s time
Wood is the main heat in about one Marshall owner home in thirteen, often with a propane furnace standing by. One that only runs when the stove is out can look fine at thirty while its parts go out of production. If it struggles on its first start of the season, get it priced.
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.
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.
Permits, locally
Fauquier County wants a permit for any fuel-fired appliance, so a gas or propane furnace replacement is permit work even in the same spot. Trade permits need no plans, and usually no zoning approval. 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.
Around Marshall a furnace often splits the work with a heat pump or a wood stove. That changes the right size, and how the thermostat hands off between them.
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.
Thank you very much for the great work. The HVAC installation, turned out perfectly. I will recommend SwiftPro service to people I know.
Where we work
Next door to Marshall: Rectortown, Delaplane, The Plains, Orlean and Broad Run.
Questions
Price both. Close to two Marshall owner homes in three already heat with electricity, so it’s a familiar switch here, and with nothing else on the tank a heat pump system could retire it. The HVAC replacement cost estimator prices both for your house.
Often the venting. On Anderson Avenue or West Main Street an older furnace may vent up a masonry chimney, while a high-efficiency one vents out a side wall in plastic pipe. If a propane water heater shares that chimney, the written price should say how it vents afterward.
$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 Marshall 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.