Open 24/7 for emergencies
Furnace and AC replacement in Hamilton runs $8,898 to $23,000 installed. Piped gas is rare here, so the new furnace will almost always burn propane.
Price range
$8,898-$23,000
8yrs @ 7.99%
$126/mo
15yrs @ 9.99%
$96/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
One of our technicians with a new Trane outdoor unit he just installed beside a Northern Virginia house.
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
$8,898 to $23,000 installed for a furnace and air conditioner replaced together, 2 to 5 ton, from the same price book as our estimator. Where you land depends on the size of the house, the efficiency you pick, and what the ductwork and venting need.
Furnace and AC together, installed
$8,898 to $23,000
or $148/mo at 0% APR for 60 months
Furnace alone, keeping your AC
$4,285 to $14,040
or $71/mo at 0% APR for 60 months
Heat pump system instead
$8,499 to $21,650
or $142/mo at 0% APR for 60 months
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 estimator gives your house its own number. Then we measure, and the price is in writing before anything is ordered.
Two years of labor come with every install. Monthly plans are on our financing page.
What’s different in Hamilton
The Purcellville weather station, 2.6 miles west-northwest of Hamilton, averages 30 days a year at 90 degrees or more, and July’s average low there, 65.5, means the nights still cool off. That rewards an air conditioner sized to the house, not oversized: a big unit cools fast, shuts off before it pulls the damp out, and leaves the rooms clammy.
Hamilton’s storms come with trees. On July 25, 2010, thunderstorm winds estimated at 57 knots left at least thirty trees down across Hamilton, the fire department reported. On July 21, 2019, winds estimated at 61 knots damaged a roof in the 39000 block of Meadowlark Drive and put trees down between town and the Route 9 and Route 704 intersection, a road Tropical Storm Irene’s fallen trees closed in 2011. A limb through the top of a twenty-year-old outdoor unit usually ends the repair conversation.
Fuel decides the pair. In the 373 owner homes on propane, it’s a furnace burning propane with an air conditioner or heat pump outside, $8,898 to $23,000 installed for both. The 665 all-electric homes have an air handler with backup strips instead, and their matching swap is a heat pump system, $8,499 to $21,650. If the outdoor unit is newer than the furnace, it may be the furnace alone at $4,285 to $14,040.
The Census dates 386 homes in 20158 to the 2000s and 271 to the 2010s, so the first builder pairs have passed twenty years, and an outdoor unit set before 2010 most likely runs on R-22. The 303 from the 1970s often keep their first ductwork, so measure it before sizing a new pair.
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
ZIP 20158 as a whole: every Hamilton address, the Town and the countryside around it. The Census place for the Town alone has too few homes for steady figures.
When it’s time
Shut it off at the thermostat and walk out to the unit first. Look for bent fins, a dented top, a limb on the line set or a disconnect box knocked loose, and call us to check it all before it runs. If the unit has seen twenty summers, we’ll price the repair and the pair side by side.
Where a lot of homes heat with electricity, the indoor half is often an air handler, and the like-for-like swap is a heat pump system, $8,499 to $21,650 installed.
Plenty of houses built since 2000 still run the builder’s furnace and AC. They wear out on about the same schedule, so when one goes, price the pair.
Choosing who installs it
Ask every company that quotes the job, us included.
A house on an open rise and one under big trees cool differently, and a finished basement changes the math. Ask whether the quote came from a load calculation on your house as it is now.
The old size is a guess somebody made years ago. Ask whether they measure the house and check the ductwork first. Too big short cycles; too small runs all afternoon in August.
Furnace, outdoor unit, matching coil, refrigerant lines, thermostat, permit and hauling the old one away. If it isn’t on the paper, ask.
Our free second opinion looks at the system you were quoted on and tells you what it actually needs, with our price if you want it.
Two of our crew going over a work order before the day's calls.
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.
From our Google reviews
5.0 stars across 1,132 reviews. Read them on our reviews page.
Hard working crew that removed old system and installed new system in a professional manner.
Where we work
Next door to Hamilton: Paeonian Springs, Waterford, Purcellville, Leesburg and Lovettsville.
Questions
No, Loudoun County does, inside the town limits and out. Its fee schedule lists adding, replacing or relocating central heating and air conditioning as permit work, and a propane furnace also takes a fuel gas permit, with no plans needed since October 1, 2025 when the BTUs and location stay the same.
If both are original to a 2000s house, yes. Chosen in the fall, a system gets measured and compared; chosen the morning after a July storm, it gets picked in a hurry. The HVAC replacement estimator gives your range first, and if a repair turns up instead, a diagnostic visit costs $99.
$8,898 to $23,000 installed for the pair, by size and efficiency. A furnace alone, keeping your AC, is $4,285 to $14,040. The HVAC replacement estimator gives your house its own number.
No. If the AC is young and only the furnace failed, replace the furnace. If they’re the same age, do both: a new outdoor unit needs a matched coil, and one built for the old refrigerant isn’t rated for the new one.
Ready when you are
Call, send the form at the top, or take the HVAC replacement estimator first. We measure before we quote, and if a repair makes more sense than a new system, 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 Hamilton 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.