It short-cycles on a mild day
If the boiler fires and stops every few minutes on a mild day, the aquastat or the limit control may be faulty, or the boiler may be bigger than the house needs. The $99 diagnostic tells you which.
Middleburg’s older houses keep its boilers; most burn propane, the tune-up is $99, and replacing one runs $9,900 to $16,500.
Price range
$9,900-$16,500
8yrs @ 7.99%
$140/mo
15yrs @ 9.99%
$106/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 in a Northern Virginia basement. The same team tunes up, repairs and replaces boilers.
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
A new boiler runs $9,900 to $16,500 installed, the range of our own boiler replacements; a condensing or combi boiler lands at $12,782 to $16,500. A tune-up is $99 a system.
High-efficiency condensing boiler or combi boiler, installed
$12,782 to $16,500
or $213/mo at 0% APR for 60 months
Cast iron boiler on the chimney, replaced like for like, installed
$9,900 to $13,690
or $165/mo at 0% APR for 60 months
Boiler tune-up, one system
$99
Boiler repair diagnostic visit
$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
A repair starts with the $99 diagnostic. If the fix is a circulator pump, a valve or an expansion tank, you get that price in writing before we start, and you decide.
Want a closer number before anyone comes out? The boiler estimator asks a few questions about yours and shows the range for that job.
What’s different in Middleburg
Piped gas heats only 41 of the 927 owner homes across ZIP 20117. Propane from a tank on the property heats 187 and electricity 582, so a Middleburg boiler is most often a propane boiler. More than a third of owner homes here went up before 1960 and about half before 1980, and those older houses are where hot water heat and radiators are. Four in five owner homes across the ZIP stand detached, and more than a quarter of the homes are let to tenants.
Many of those houses sit in the Historic District, where an exterior change visible from a public street needs a Certificate of Appropriateness from the Historic District Review Committee before work begins. On a front wall, that includes a new plastic vent for a condensing boiler; a cast iron boiler that stays on its chimney changes nothing outside.
Loudoun County issues the building permit, and inside the town limits the Town also requires a Zoning Location Permit for any job that needs a County building permit. A boiler replacement in town therefore takes both, so the order matters when the boiler has already quit. If the boiler is already failing, start the zoning step early.
The Purcellville station, 12 miles north, averages 24.5 degrees on a January night, and Middleburg read 4 below zero on January 23, 2025. A boiler in a house that old is often the oldest thing in it after the radiators, and a fall look at the pressure, the expansion tank and the circulator is cheaper than a January call. The radiators in those houses usually outlast several boilers, so a replacement is normally a boiler-only job.
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
ZIP 20117 as a whole: every Middleburg address, the Town and the farms around it, about a tenth of the land in Fauquier County. The Census place for the Town alone has too few homes for steady figures.
What it’s telling you
If the boiler fires and stops every few minutes on a mild day, the aquastat or the limit control may be faulty, or the boiler may be bigger than the house needs. The $99 diagnostic tells you which.
Close view of a SwiftPro boiler installation in Northern Virginia showing the expansion tank, automatic air vent, fill valve and the vent connector into the chimney.
Safety and paperwork
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.
In its fall clock-change reminder, Loudoun County’s fire and rescue system tells residents to check their carbon monoxide alarms, and recommends one outside each sleeping area and on each level of the home, tested monthly. Source.
Loudoun County Fire and Rescue says to have heating equipment and chimneys cleaned and inspected every year by a qualified professional, and to keep anything that can burn at least three feet from all heating equipment. Source.
Our Virginia Class A contractor license, 2705192276, is on the side of the van.
Choosing who works on it
Questions to ask anybody who quotes you, us included.
In the Historic District, ask whether the quote assumes the old chimney or a new wall vent, and who brings the Certificate of Appropriateness question to the committee.
A hot water boiler is half heating system (the burner, gas valve, flue and controls) and half plumbing (the water loop, circulator pumps, expansion tank, relief valve and zone valves). We hold a Virginia Class A license and run separate heating and plumbing teams, so each half gets a tech who does that trade every day.
A new boiler can stay on the chimney or vent out the wall in plastic pipe. A good quote says which, and whether the chimney needs a liner, because that’s where two quotes for the same boiler usually split.
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.
Replacement for my broken gas water boiler was professionally done and in a timely manner. The technicians knew exactly what they were doing.
Where we work
Next door to Middleburg: Philomont, Aldie, Round Hill, Hamilton and Purcellville.
Questions
Yes: Loudoun County’s building permit and the Town’s Zoning Location Permit, which the Town requires for any job that needs the County permit.
With gas reaching so few homes, usually: a propane boiler on the existing radiators costs $9,900 to $16,500 installed, and if the house can vent through a side wall, a condensing model runs $12,782 to $16,500.
No. We work on hot water boilers, the kind that heat radiators or baseboard, on natural gas or propane. If yours is steam or burns oil, we’ll tell you on the phone, and a switch to a heat pump or a gas or propane boiler is ours to price.
Ready when you are
Call any time: we run 24/7 emergency service. Or send the form at the top. A tune-up is $99, a repair starts with the $99 diagnostic, and a new boiler gets a written price before any work.
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 Middleburg 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.