Open 24/7 for emergencies
A new gas or propane furnace in Manassas runs $4,285 to $14,040 installed, keeping your AC. On the county side, a little over half the owner homes burn 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 Manassas
A furnace on its own is a job for the houses that burn gas or propane. Inside the City of Manassas that’s a little under half the owner homes; nearly all the rest heat with electricity, which in a City house from the 1980s usually means a heat pump instead. On the county side gas has the edge: by the Census Bureau’s estimates, roughly 720 of Loch Lomond’s 976 owner homes heat with it, about 2,100 of Sudley’s 3,400 and about 1,800 of Independent Hill’s 3,040.
They’re also three ages of furnace. Loch Lomond’s median owner home dates from 1968, so the basement furnace there today is a replacement of a replacement. Sudley’s median is 1977 and close to half its homes are townhouses, where the furnace usually stands in a utility closet and the new one comes in the way the old one leaves. Independent Hill is the young end, half of it built since 2000, and plenty of its houses still run the builder’s furnace.
Keeping the air conditioner makes sense when it’s worth keeping. Read the outdoor unit’s label for its year before anybody quotes. Well short of fifteen and cooling fine, it stays, and the new furnace gets matched to the coil on top of it. Same year as the furnace? Look at the pair’s range too, $8,898 to $23,000 installed; the HVAC replacement cost estimator prices both ways.
Buckhall is the propane corner of Manassas: roughly 460 of its 5,968 owner homes burn it, more than anywhere else on this page. Propane furnaces are ours to replace as much as natural gas ones: the new one gets its burner and gas valve changed over for propane before the first fire, and the written quote names the fuel.
Neighborhood by neighborhood
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 |
|---|---|---|---|---|
| City of Manassas | 1985 | single-family houses, about 4 in 10 | electricity, about 5 in 10 | Mostly electric heat; gas furnaces are the minority. |
| Buckhall | 1995 | single-family houses, about 8 in 10 | electricity, about 5 in 10 | A mix of gas furnaces and heat pumps. |
| Sudley | 1977 | townhouses, about 4 in 10 | gas, about 6 in 10 | Townhouse furnaces in closets and attics. |
| Independent Hill | 2000 | single-family houses, nearly all | gas, about 6 in 10 | Builder gas furnaces, many now near twenty years old. |
| Bull Run | 1995 | condo and apartment buildings, about 5 in 10 | gas, about 7 in 10 | Condo and apartment buildings: compact furnaces in closets. |
| Yorkshire | 1984 | single-family houses, about 4 in 10 | gas, about 5 in 10 | 1980s and 90s houses, many on their second furnace. |
| Loch Lomond | 1968 | single-family houses, nearly all | gas, about 7 in 10 | Gas furnaces on their second or third round, often on a chimney shared with the water heater. |
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
The whole City sits in ZIP 20110. It runs its own water, sewer and electric service.
Sudley and Bull Run in 20109, Yorkshire and most of Buckhall in 20111, Independent Hill in 20112, plus the county edges of 20110.
When it’s time
In a 1960s or 70s Loch Lomond or Sudley house, the furnace often ended up boxed into a closet when the lower level became living space. A gas furnace needs air to burn, and a crowded closet starves it. A sealed furnace that draws its air from outdoors is one answer.
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
The City lists gas clothes dryers, and replacing a gas dryer, furnace, stove or heater, as mechanical permit work. 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.
A Manassas address can sit in the City of Manassas, the City of Manassas Park or Prince William County, each with its own permit office. Ask which one your furnace job goes through. The ZIP code alone won’t say.
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.
Excellent service and attention to detail. James was super thorough and explained everything to me. I highly recommend them for any plumbing needs
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!
Where we work
Next door to Manassas: Bristow, Nokesville, Clifton, Centreville and Catharpin.
Questions
Same furnace, same price book, a different permit office. Manassas Park is its own city inside 20111, and its building office wants a permit for the replacement of any gas appliance. Seven in ten of its owners heat with gas.
Yes, whenever it burns gas or propane: the county’s guide to permits puts replacing a gas furnace in its always column, like for like or not. Every Manassas address outside the city limits files there; inside the City, the City’s own office handles it.
$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 Manassas 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.